From c33bd8354f3a3bb26a98d2b6bf600b7b35657328 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 12 Sep 2013 15:13:19 -0700 Subject: memcg: remove redundant code in mem_cgroup_force_empty_write() vfs guarantees the cgroup won't be destroyed, so it's redundant to get a css reference. Signed-off-by: Li Zefan Acked-by: Michal Hocko Cc: KAMEZAWA Hiroyuki Cc: Johannes Weiner Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c6bd28edd533..fe6b9f96abdd 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4990,18 +4990,12 @@ static int mem_cgroup_force_empty_write(struct cgroup_subsys_state *css, unsigned int event) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); - int ret; if (mem_cgroup_is_root(memcg)) return -EINVAL; - css_get(&memcg->css); - ret = mem_cgroup_force_empty(memcg); - css_put(&memcg->css); - - return ret; + return mem_cgroup_force_empty(memcg); } - static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, struct cftype *cft) { -- cgit v1.2.3 From 3b38722efd9f66da63bbbd41520c2e6fa9db3d68 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 12 Sep 2013 15:13:21 -0700 Subject: memcg, vmscan: integrate soft reclaim tighter with zone shrinking code This patchset is sitting out of tree for quite some time without any objections. I would be really happy if it made it into 3.12. I do not want to push it too hard but I think this work is basically ready and waiting more doesn't help. The basic idea is quite simple. Pull soft reclaim into shrink_zone in the first step and get rid of the previous soft reclaim infrastructure. shrink_zone is done in two passes now. First it tries to do the soft limit reclaim and it falls back to reclaim-all mode if no group is over the limit or no pages have been scanned. The second pass happens at the same priority so the only time we waste is the memcg tree walk which has been updated in the third step to have only negligible overhead. As a bonus we will get rid of a _lot_ of code by this and soft reclaim will not stand out like before when it wasn't integrated into the zone shrinking code and it reclaimed at priority 0 (the testing results show that some workloads suffers from such an aggressive reclaim). The clean up is in a separate patch because I felt it would be easier to review that way. The second step is soft limit reclaim integration into targeted reclaim. It should be rather straight forward. Soft limit has been used only for the global reclaim so far but it makes sense for any kind of pressure coming from up-the-hierarchy, including targeted reclaim. The third step (patches 4-8) addresses the tree walk overhead by enhancing memcg iterators to enable skipping whole subtrees and tracking number of over soft limit children at each level of the hierarchy. This information is updated same way the old soft limit tree was updated (from memcg_check_events) so we shouldn't see an additional overhead. In fact mem_cgroup_update_soft_limit is much simpler than tree manipulation done previously. __shrink_zone uses mem_cgroup_soft_reclaim_eligible as a predicate for mem_cgroup_iter so the decision whether a particular group should be visited is done at the iterator level which allows us to decide to skip the whole subtree as well (if there is no child in excess). This reduces the tree walk overhead considerably. * TEST 1 ======== My primary test case was a parallel kernel build with 2 groups (make is running with -j8 with a distribution .config in a separate cgroup without any hard limit) on a 32 CPU machine booted with 1GB memory and both builds run taskset to Node 0 cpus. I was mostly interested in 2 setups. Default - no soft limit set and - and 0 soft limit set to both groups. The first one should tell us whether the rework regresses the default behavior while the second one should show us improvements in an extreme case where both workloads are always over the soft limit. /usr/bin/time -v has been used to collect the statistics and each configuration had 3 runs after fresh boot without any other load on the system. base is mmotm-2013-07-18-16-40 rework all 8 patches applied on top of base * No-limit User no-limit/base: min: 651.92 max: 672.65 avg: 664.33 std: 8.01 runs: 6 no-limit/rework: min: 657.34 [100.8%] max: 668.39 [99.4%] avg: 663.13 [99.8%] std: 3.61 runs: 6 System no-limit/base: min: 69.33 max: 71.39 avg: 70.32 std: 0.79 runs: 6 no-limit/rework: min: 69.12 [99.7%] max: 71.05 [99.5%] avg: 70.04 [99.6%] std: 0.59 runs: 6 Elapsed no-limit/base: min: 398.27 max: 422.36 avg: 408.85 std: 7.74 runs: 6 no-limit/rework: min: 386.36 [97.0%] max: 438.40 [103.8%] avg: 416.34 [101.8%] std: 18.85 runs: 6 The results are within noise. Elapsed time has a bigger variance but the average looks good. * 0-limit User 0-limit/base: min: 573.76 max: 605.63 avg: 585.73 std: 12.21 runs: 6 0-limit/rework: min: 645.77 [112.6%] max: 666.25 [110.0%] avg: 656.97 [112.2%] std: 7.77 runs: 6 System 0-limit/base: min: 69.57 max: 71.13 avg: 70.29 std: 0.54 runs: 6 0-limit/rework: min: 68.68 [98.7%] max: 71.40 [100.4%] avg: 69.91 [99.5%] std: 0.87 runs: 6 Elapsed 0-limit/base: min: 1306.14 max: 1550.17 avg: 1430.35 std: 90.86 runs: 6 0-limit/rework: min: 404.06 [30.9%] max: 465.94 [30.1%] avg: 434.81 [30.4%] std: 22.68 runs: 6 The improvement is really huge here (even bigger than with my previous testing and I suspect that this highly depends on the storage). Page fault statistics tell us at least part of the story: Minor 0-limit/base: min: 37180461.00 max: 37319986.00 avg: 37247470.00 std: 54772.71 runs: 6 0-limit/rework: min: 36751685.00 [98.8%] max: 36805379.00 [98.6%] avg: 36774506.33 [98.7%] std: 17109.03 runs: 6 Major 0-limit/base: min: 170604.00 max: 221141.00 avg: 196081.83 std: 18217.01 runs: 6 0-limit/rework: min: 2864.00 [1.7%] max: 10029.00 [4.5%] avg: 5627.33 [2.9%] std: 2252.71 runs: 6 Same as with my previous testing Minor faults are more or less within noise but Major fault count is way bellow the base kernel. While this looks as a nice win it is fair to say that 0-limit configuration is quite artificial. So I was playing with 0-no-limit loads as well. * TEST 2 ======== The following results are from 2 groups configuration on a 16GB machine (single NUMA node). - A running stream IO (dd if=/dev/zero of=local.file bs=1024) with 2*TotalMem with 0 soft limit. - B running a mem_eater which consumes TotalMem-1G without any limit. The mem_eater consumes the memory in 100 chunks with 1s nap after each mmap+poppulate so that both loads have chance to fight for the memory. The expected result is that B shouldn't be reclaimed and A shouldn't see a big dropdown in elapsed time. User base: min: 2.68 max: 2.89 avg: 2.76 std: 0.09 runs: 3 rework: min: 3.27 [122.0%] max: 3.74 [129.4%] avg: 3.44 [124.6%] std: 0.21 runs: 3 System base: min: 86.26 max: 88.29 avg: 87.28 std: 0.83 runs: 3 rework: min: 81.05 [94.0%] max: 84.96 [96.2%] avg: 83.14 [95.3%] std: 1.61 runs: 3 Elapsed base: min: 317.28 max: 332.39 avg: 325.84 std: 6.33 runs: 3 rework: min: 281.53 [88.7%] max: 298.16 [89.7%] avg: 290.99 [89.3%] std: 6.98 runs: 3 System time improved slightly as well as Elapsed. My previous testing has shown worse numbers but this again seem to depend on the storage speed. My theory is that the writeback doesn't catch up and prio-0 soft reclaim falls into wait on writeback page too often in the base kernel. The patched kernel doesn't do that because the soft reclaim is done from the kswapd/direct reclaim context. This can be seen on the following graph nicely. The A's group usage_in_bytes regurarly drops really low very often. All 3 runs http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/stream.png resp. a detail of the single run http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/stream-one-run.png mem_eater seems to be doing better as well. It gets to the full allocation size faster as can be seen on the following graph: http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/mem_eater-one-run.png /proc/meminfo collected during the test also shows that rework kernel hasn't swapped that much (well almost not at all): base: max: 123900 K avg: 56388.29 K rework: max: 300 K avg: 128.68 K kswapd and direct reclaim statistics are of no use unfortunatelly because soft reclaim is not accounted properly as the counters are hidden by global_reclaim() checks in the base kernel. * TEST 3 ======== Another test was the same configuration as TEST2 except the stream IO was replaced by a single kbuild (16 parallel jobs bound to Node0 cpus same as in TEST1) and mem_eater allocated TotalMem-200M so kbuild had only 200MB left. Kbuild did better with the rework kernel here as well: User base: min: 860.28 max: 872.86 avg: 868.03 std: 5.54 runs: 3 rework: min: 880.81 [102.4%] max: 887.45 [101.7%] avg: 883.56 [101.8%] std: 2.83 runs: 3 System base: min: 84.35 max: 85.06 avg: 84.79 std: 0.31 runs: 3 rework: min: 85.62 [101.5%] max: 86.09 [101.2%] avg: 85.79 [101.2%] std: 0.21 runs: 3 Elapsed base: min: 135.36 max: 243.30 avg: 182.47 std: 45.12 runs: 3 rework: min: 110.46 [81.6%] max: 116.20 [47.8%] avg: 114.15 [62.6%] std: 2.61 runs: 3 Minor base: min: 36635476.00 max: 36673365.00 avg: 36654812.00 std: 15478.03 runs: 3 rework: min: 36639301.00 [100.0%] max: 36695541.00 [100.1%] avg: 36665511.00 [100.0%] std: 23118.23 runs: 3 Major base: min: 14708.00 max: 53328.00 avg: 31379.00 std: 16202.24 runs: 3 rework: min: 302.00 [2.1%] max: 414.00 [0.8%] avg: 366.33 [1.2%] std: 47.22 runs: 3 Again we can see a significant improvement in Elapsed (it also seems to be more stable), there is a huge dropdown for the Major page faults and much more swapping: base: max: 583736 K avg: 112547.43 K rework: max: 4012 K avg: 124.36 K Graphs from all three runs show the variability of the kbuild quite nicely. It even seems that it took longer after every run with the base kernel which would be quite surprising as the source tree for the build is removed and caches are dropped after each run so the build operates on a freshly extracted sources everytime. http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/kbuild-mem_eater.png My other testing shows that this is just a matter of timing and other runs behave differently the std for Elapsed time is similar ~50. Example of other three runs: http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/kbuild-mem_eater2.png So to wrap this up. The series is still doing good and improves the soft limit. The testing results for bunch of cgroups with both stream IO and kbuild loads can be found in "memcg: track children in soft limit excess to improve soft limit". This patch: Memcg soft reclaim has been traditionally triggered from the global reclaim paths before calling shrink_zone. mem_cgroup_soft_limit_reclaim then picked up a group which exceeds the soft limit the most and reclaimed it with 0 priority to reclaim at least SWAP_CLUSTER_MAX pages. The infrastructure requires per-node-zone trees which hold over-limit groups and keep them up-to-date (via memcg_check_events) which is not cost free. Although this overhead hasn't turned out to be a bottle neck the implementation is suboptimal because mem_cgroup_update_tree has no idea which zones consumed memory over the limit so we could easily end up having a group on a node-zone tree having only few pages from that node-zone. This patch doesn't try to fix node-zone trees management because it seems that integrating soft reclaim into zone shrinking sounds much easier and more appropriate for several reasons. First of all 0 priority reclaim was a crude hack which might lead to big stalls if the group's LRUs are big and hard to reclaim (e.g. a lot of dirty/writeback pages). Soft reclaim should be applicable also to the targeted reclaim which is awkward right now without additional hacks. Last but not least the whole infrastructure eats quite some code. After this patch shrink_zone is done in 2 passes. First it tries to do the soft reclaim if appropriate (only for global reclaim for now to keep compatible with the original state) and fall back to ignoring soft limit if no group is eligible to soft reclaim or nothing has been scanned during the first pass. Only groups which are over their soft limit or any of their parents up the hierarchy is over the limit are considered eligible during the first pass. Soft limit tree which is not necessary anymore will be removed in the follow up patch to make this patch smaller and easier to review. Signed-off-by: Michal Hocko Reviewed-by: Glauber Costa Reviewed-by: Tejun Heo Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: Ying Han Cc: Hugh Dickins Cc: Michel Lespinasse Cc: Greg Thelen Cc: KOSAKI Motohiro Cc: Balbir Singh Cc: Glauber Costa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 10 +-- mm/memcontrol.c | 163 ++++++--------------------------------------- mm/vmscan.c | 62 +++++++++-------- 3 files changed, 60 insertions(+), 175 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 6c416092e324..4b78661c68d0 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -180,9 +180,7 @@ static inline void mem_cgroup_dec_page_stat(struct page *page, mem_cgroup_update_page_stat(page, idx, -1); } -unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, - gfp_t gfp_mask, - unsigned long *total_scanned); +bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg); void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx); static inline void mem_cgroup_count_vm_event(struct mm_struct *mm, @@ -359,11 +357,9 @@ static inline void mem_cgroup_dec_page_stat(struct page *page, } static inline -unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, - gfp_t gfp_mask, - unsigned long *total_scanned) +bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg) { - return 0; + return false; } static inline void mem_cgroup_split_huge_fixup(struct page *head) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index fe6b9f96abdd..6c32271a31c5 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2004,57 +2004,28 @@ static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) } #endif -static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, - struct zone *zone, - gfp_t gfp_mask, - unsigned long *total_scanned) -{ - struct mem_cgroup *victim = NULL; - int total = 0; - int loop = 0; - unsigned long excess; - unsigned long nr_scanned; - struct mem_cgroup_reclaim_cookie reclaim = { - .zone = zone, - .priority = 0, - }; - - excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT; - - while (1) { - victim = mem_cgroup_iter(root_memcg, victim, &reclaim); - if (!victim) { - loop++; - if (loop >= 2) { - /* - * If we have not been able to reclaim - * anything, it might because there are - * no reclaimable pages under this hierarchy - */ - if (!total) - break; - /* - * We want to do more targeted reclaim. - * excess >> 2 is not to excessive so as to - * reclaim too much, nor too less that we keep - * coming back to reclaim from this cgroup - */ - if (total >= (excess >> 2) || - (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) - break; - } - continue; - } - if (!mem_cgroup_reclaimable(victim, false)) - continue; - total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, - zone, &nr_scanned); - *total_scanned += nr_scanned; - if (!res_counter_soft_limit_excess(&root_memcg->res)) - break; +/* + * A group is eligible for the soft limit reclaim if it is + * a) is over its soft limit + * b) any parent up the hierarchy is over its soft limit + */ +bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg) +{ + struct mem_cgroup *parent = memcg; + + if (res_counter_soft_limit_excess(&memcg->res)) + return true; + + /* + * If any parent up the hierarchy is over its soft limit then we + * have to obey and reclaim from this group as well. + */ + while((parent = parent_mem_cgroup(parent))) { + if (res_counter_soft_limit_excess(&parent->res)) + return true; } - mem_cgroup_iter_break(root_memcg, victim); - return total; + + return false; } /* @@ -4727,98 +4698,6 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, return ret; } -unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, - gfp_t gfp_mask, - unsigned long *total_scanned) -{ - unsigned long nr_reclaimed = 0; - struct mem_cgroup_per_zone *mz, *next_mz = NULL; - unsigned long reclaimed; - int loop = 0; - struct mem_cgroup_tree_per_zone *mctz; - unsigned long long excess; - unsigned long nr_scanned; - - if (order > 0) - return 0; - - mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); - /* - * This loop can run a while, specially if mem_cgroup's continuously - * keep exceeding their soft limit and putting the system under - * pressure - */ - do { - if (next_mz) - mz = next_mz; - else - mz = mem_cgroup_largest_soft_limit_node(mctz); - if (!mz) - break; - - nr_scanned = 0; - reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, - gfp_mask, &nr_scanned); - nr_reclaimed += reclaimed; - *total_scanned += nr_scanned; - spin_lock(&mctz->lock); - - /* - * If we failed to reclaim anything from this memory cgroup - * it is time to move on to the next cgroup - */ - next_mz = NULL; - if (!reclaimed) { - do { - /* - * Loop until we find yet another one. - * - * By the time we get the soft_limit lock - * again, someone might have aded the - * group back on the RB tree. Iterate to - * make sure we get a different mem. - * mem_cgroup_largest_soft_limit_node returns - * NULL if no other cgroup is present on - * the tree - */ - next_mz = - __mem_cgroup_largest_soft_limit_node(mctz); - if (next_mz == mz) - css_put(&next_mz->memcg->css); - else /* next_mz == NULL or other memcg */ - break; - } while (1); - } - __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); - excess = res_counter_soft_limit_excess(&mz->memcg->res); - /* - * One school of thought says that we should not add - * back the node to the tree if reclaim returns 0. - * But our reclaim could return 0, simply because due - * to priority we are exposing a smaller subset of - * memory to reclaim from. Consider this as a longer - * term TODO. - */ - /* If excess == 0, no tree ops */ - __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess); - spin_unlock(&mctz->lock); - css_put(&mz->memcg->css); - loop++; - /* - * Could not reclaim anything and there are no more - * mem cgroups to try or we seem to be looping without - * reclaiming anything. - */ - if (!nr_reclaimed && - (next_mz == NULL || - loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) - break; - } while (!nr_reclaimed); - if (next_mz) - css_put(&next_mz->memcg->css); - return nr_reclaimed; -} - /** * mem_cgroup_force_empty_list - clears LRU of a group * @memcg: group to clear diff --git a/mm/vmscan.c b/mm/vmscan.c index fe715daeb8bc..cf4643807ec2 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -139,11 +139,21 @@ static bool global_reclaim(struct scan_control *sc) { return !sc->target_mem_cgroup; } + +static bool mem_cgroup_should_soft_reclaim(struct scan_control *sc) +{ + return !mem_cgroup_disabled() && global_reclaim(sc); +} #else static bool global_reclaim(struct scan_control *sc) { return true; } + +static bool mem_cgroup_should_soft_reclaim(struct scan_control *sc) +{ + return false; +} #endif unsigned long zone_reclaimable_pages(struct zone *zone) @@ -2130,7 +2140,8 @@ static inline bool should_continue_reclaim(struct zone *zone, } } -static void shrink_zone(struct zone *zone, struct scan_control *sc) +static void +__shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) { unsigned long nr_reclaimed, nr_scanned; @@ -2149,6 +2160,12 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc) do { struct lruvec *lruvec; + if (soft_reclaim && + !mem_cgroup_soft_reclaim_eligible(memcg)) { + memcg = mem_cgroup_iter(root, memcg, &reclaim); + continue; + } + lruvec = mem_cgroup_zone_lruvec(zone, memcg); shrink_lruvec(lruvec, sc); @@ -2179,6 +2196,24 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc) sc->nr_scanned - nr_scanned, sc)); } + +static void shrink_zone(struct zone *zone, struct scan_control *sc) +{ + bool do_soft_reclaim = mem_cgroup_should_soft_reclaim(sc); + unsigned long nr_scanned = sc->nr_scanned; + + __shrink_zone(zone, sc, do_soft_reclaim); + + /* + * No group is over the soft limit or those that are do not have + * pages in the zone we are reclaiming so we have to reclaim everybody + */ + if (do_soft_reclaim && (sc->nr_scanned == nr_scanned)) { + __shrink_zone(zone, sc, false); + return; + } +} + /* Returns true if compaction should go ahead for a high-order request */ static inline bool compaction_ready(struct zone *zone, struct scan_control *sc) { @@ -2240,8 +2275,6 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) { struct zoneref *z; struct zone *zone; - unsigned long nr_soft_reclaimed; - unsigned long nr_soft_scanned; bool aborted_reclaim = false; /* @@ -2281,18 +2314,6 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) continue; } } - /* - * This steals pages from memory cgroups over softlimit - * and returns the number of reclaimed pages and - * scanned pages. This works for global memory pressure - * and balancing, not for a memcg's limit. - */ - nr_soft_scanned = 0; - nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone, - sc->order, sc->gfp_mask, - &nr_soft_scanned); - sc->nr_reclaimed += nr_soft_reclaimed; - sc->nr_scanned += nr_soft_scanned; /* need some check for avoid more shrink_zone() */ } @@ -2880,8 +2901,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, { int i; int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */ - unsigned long nr_soft_reclaimed; - unsigned long nr_soft_scanned; struct scan_control sc = { .gfp_mask = GFP_KERNEL, .priority = DEF_PRIORITY, @@ -2996,15 +3015,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, sc.nr_scanned = 0; - nr_soft_scanned = 0; - /* - * Call soft limit reclaim before calling shrink_zone. - */ - nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone, - order, sc.gfp_mask, - &nr_soft_scanned); - sc.nr_reclaimed += nr_soft_reclaimed; - /* * There should be no need to raise the scanning * priority if enough pages are already being scanned -- cgit v1.2.3 From e883110aad718b65de658db77387aaa69cce996d Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 12 Sep 2013 15:13:23 -0700 Subject: memcg: get rid of soft-limit tree infrastructure Now that the soft limit is integrated to the reclaim directly the whole soft-limit tree infrastructure is not needed anymore. Rip it out. Signed-off-by: Michal Hocko Reviewed-by: Glauber Costa Reviewed-by: Tejun Heo Cc: Balbir Singh Cc: Greg Thelen Cc: Hugh Dickins Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Michel Lespinasse Cc: Ying Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 265 +------------------------------------------------------- 1 file changed, 2 insertions(+), 263 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6c32271a31c5..87a448dd9c10 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -39,7 +39,6 @@ #include #include #include -#include #include #include #include @@ -139,7 +138,6 @@ static const char * const mem_cgroup_lru_names[] = { */ enum mem_cgroup_events_target { MEM_CGROUP_TARGET_THRESH, - MEM_CGROUP_TARGET_SOFTLIMIT, MEM_CGROUP_TARGET_NUMAINFO, MEM_CGROUP_NTARGETS, }; @@ -175,10 +173,6 @@ struct mem_cgroup_per_zone { struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1]; - struct rb_node tree_node; /* RB tree node */ - unsigned long long usage_in_excess;/* Set to the value by which */ - /* the soft limit is exceeded*/ - bool on_tree; struct mem_cgroup *memcg; /* Back pointer, we cannot */ /* use container_of */ }; @@ -187,26 +181,6 @@ struct mem_cgroup_per_node { struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; }; -/* - * Cgroups above their limits are maintained in a RB-Tree, independent of - * their hierarchy representation - */ - -struct mem_cgroup_tree_per_zone { - struct rb_root rb_root; - spinlock_t lock; -}; - -struct mem_cgroup_tree_per_node { - struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; -}; - -struct mem_cgroup_tree { - struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; -}; - -static struct mem_cgroup_tree soft_limit_tree __read_mostly; - struct mem_cgroup_threshold { struct eventfd_ctx *eventfd; u64 threshold; @@ -444,7 +418,6 @@ static bool move_file(void) * limit reclaim to prevent infinite loops, if they ever occur. */ #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 -#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 enum charge_type { MEM_CGROUP_CHARGE_TYPE_CACHE = 0, @@ -671,164 +644,6 @@ page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) return mem_cgroup_zoneinfo(memcg, nid, zid); } -static struct mem_cgroup_tree_per_zone * -soft_limit_tree_node_zone(int nid, int zid) -{ - return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; -} - -static struct mem_cgroup_tree_per_zone * -soft_limit_tree_from_page(struct page *page) -{ - int nid = page_to_nid(page); - int zid = page_zonenum(page); - - return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; -} - -static void -__mem_cgroup_insert_exceeded(struct mem_cgroup *memcg, - struct mem_cgroup_per_zone *mz, - struct mem_cgroup_tree_per_zone *mctz, - unsigned long long new_usage_in_excess) -{ - struct rb_node **p = &mctz->rb_root.rb_node; - struct rb_node *parent = NULL; - struct mem_cgroup_per_zone *mz_node; - - if (mz->on_tree) - return; - - mz->usage_in_excess = new_usage_in_excess; - if (!mz->usage_in_excess) - return; - while (*p) { - parent = *p; - mz_node = rb_entry(parent, struct mem_cgroup_per_zone, - tree_node); - if (mz->usage_in_excess < mz_node->usage_in_excess) - p = &(*p)->rb_left; - /* - * We can't avoid mem cgroups that are over their soft - * limit by the same amount - */ - else if (mz->usage_in_excess >= mz_node->usage_in_excess) - p = &(*p)->rb_right; - } - rb_link_node(&mz->tree_node, parent, p); - rb_insert_color(&mz->tree_node, &mctz->rb_root); - mz->on_tree = true; -} - -static void -__mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, - struct mem_cgroup_per_zone *mz, - struct mem_cgroup_tree_per_zone *mctz) -{ - if (!mz->on_tree) - return; - rb_erase(&mz->tree_node, &mctz->rb_root); - mz->on_tree = false; -} - -static void -mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, - struct mem_cgroup_per_zone *mz, - struct mem_cgroup_tree_per_zone *mctz) -{ - spin_lock(&mctz->lock); - __mem_cgroup_remove_exceeded(memcg, mz, mctz); - spin_unlock(&mctz->lock); -} - - -static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) -{ - unsigned long long excess; - struct mem_cgroup_per_zone *mz; - struct mem_cgroup_tree_per_zone *mctz; - int nid = page_to_nid(page); - int zid = page_zonenum(page); - mctz = soft_limit_tree_from_page(page); - - /* - * Necessary to update all ancestors when hierarchy is used. - * because their event counter is not touched. - */ - for (; memcg; memcg = parent_mem_cgroup(memcg)) { - mz = mem_cgroup_zoneinfo(memcg, nid, zid); - excess = res_counter_soft_limit_excess(&memcg->res); - /* - * We have to update the tree if mz is on RB-tree or - * mem is over its softlimit. - */ - if (excess || mz->on_tree) { - spin_lock(&mctz->lock); - /* if on-tree, remove it */ - if (mz->on_tree) - __mem_cgroup_remove_exceeded(memcg, mz, mctz); - /* - * Insert again. mz->usage_in_excess will be updated. - * If excess is 0, no tree ops. - */ - __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess); - spin_unlock(&mctz->lock); - } - } -} - -static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) -{ - int node, zone; - struct mem_cgroup_per_zone *mz; - struct mem_cgroup_tree_per_zone *mctz; - - for_each_node(node) { - for (zone = 0; zone < MAX_NR_ZONES; zone++) { - mz = mem_cgroup_zoneinfo(memcg, node, zone); - mctz = soft_limit_tree_node_zone(node, zone); - mem_cgroup_remove_exceeded(memcg, mz, mctz); - } - } -} - -static struct mem_cgroup_per_zone * -__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) -{ - struct rb_node *rightmost = NULL; - struct mem_cgroup_per_zone *mz; - -retry: - mz = NULL; - rightmost = rb_last(&mctz->rb_root); - if (!rightmost) - goto done; /* Nothing to reclaim from */ - - mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); - /* - * Remove the node now but someone else can add it back, - * we will to add it back at the end of reclaim to its correct - * position in the tree. - */ - __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); - if (!res_counter_soft_limit_excess(&mz->memcg->res) || - !css_tryget(&mz->memcg->css)) - goto retry; -done: - return mz; -} - -static struct mem_cgroup_per_zone * -mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) -{ - struct mem_cgroup_per_zone *mz; - - spin_lock(&mctz->lock); - mz = __mem_cgroup_largest_soft_limit_node(mctz); - spin_unlock(&mctz->lock); - return mz; -} - /* * Implementation Note: reading percpu statistics for memcg. * @@ -987,9 +802,6 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, case MEM_CGROUP_TARGET_THRESH: next = val + THRESHOLDS_EVENTS_TARGET; break; - case MEM_CGROUP_TARGET_SOFTLIMIT: - next = val + SOFTLIMIT_EVENTS_TARGET; - break; case MEM_CGROUP_TARGET_NUMAINFO: next = val + NUMAINFO_EVENTS_TARGET; break; @@ -1012,11 +824,8 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) /* threshold event is triggered in finer grain than soft limit */ if (unlikely(mem_cgroup_event_ratelimit(memcg, MEM_CGROUP_TARGET_THRESH))) { - bool do_softlimit; bool do_numainfo __maybe_unused; - do_softlimit = mem_cgroup_event_ratelimit(memcg, - MEM_CGROUP_TARGET_SOFTLIMIT); #if MAX_NUMNODES > 1 do_numainfo = mem_cgroup_event_ratelimit(memcg, MEM_CGROUP_TARGET_NUMAINFO); @@ -1024,8 +833,6 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) preempt_enable(); mem_cgroup_threshold(memcg); - if (unlikely(do_softlimit)) - mem_cgroup_update_tree(memcg, page); #if MAX_NUMNODES > 1 if (unlikely(do_numainfo)) atomic_inc(&memcg->numainfo_events); @@ -1867,6 +1674,7 @@ static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, return total; } +#if MAX_NUMNODES > 1 /** * test_mem_cgroup_node_reclaimable * @memcg: the target memcg @@ -1889,7 +1697,6 @@ static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, return false; } -#if MAX_NUMNODES > 1 /* * Always updating the nodemask is not very good - even if we have an empty @@ -1957,51 +1764,12 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) return node; } -/* - * Check all nodes whether it contains reclaimable pages or not. - * For quick scan, we make use of scan_nodes. This will allow us to skip - * unused nodes. But scan_nodes is lazily updated and may not cotain - * enough new information. We need to do double check. - */ -static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) -{ - int nid; - - /* - * quick check...making use of scan_node. - * We can skip unused nodes. - */ - if (!nodes_empty(memcg->scan_nodes)) { - for (nid = first_node(memcg->scan_nodes); - nid < MAX_NUMNODES; - nid = next_node(nid, memcg->scan_nodes)) { - - if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) - return true; - } - } - /* - * Check rest of nodes. - */ - for_each_node_state(nid, N_MEMORY) { - if (node_isset(nid, memcg->scan_nodes)) - continue; - if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) - return true; - } - return false; -} - #else int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) { return 0; } -static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) -{ - return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); -} #endif /* @@ -2876,9 +2644,7 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, unlock_page_cgroup(pc); /* - * "charge_statistics" updated event counter. Then, check it. - * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. - * if they exceeds softlimit. + * "charge_statistics" updated event counter. */ memcg_check_events(memcg, page); } @@ -5962,8 +5728,6 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) for (zone = 0; zone < MAX_NR_ZONES; zone++) { mz = &pn->zoneinfo[zone]; lruvec_init(&mz->lruvec); - mz->usage_in_excess = 0; - mz->on_tree = false; mz->memcg = memcg; } memcg->nodeinfo[node] = pn; @@ -6019,7 +5783,6 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg) int node; size_t size = memcg_size(); - mem_cgroup_remove_from_trees(memcg); free_css_id(&mem_cgroup_subsys, &memcg->css); for_each_node(node) @@ -6056,29 +5819,6 @@ struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) } EXPORT_SYMBOL(parent_mem_cgroup); -static void __init mem_cgroup_soft_limit_tree_init(void) -{ - struct mem_cgroup_tree_per_node *rtpn; - struct mem_cgroup_tree_per_zone *rtpz; - int tmp, node, zone; - - for_each_node(node) { - tmp = node; - if (!node_state(node, N_NORMAL_MEMORY)) - tmp = -1; - rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); - BUG_ON(!rtpn); - - soft_limit_tree.rb_tree_per_node[node] = rtpn; - - for (zone = 0; zone < MAX_NR_ZONES; zone++) { - rtpz = &rtpn->rb_tree_per_zone[zone]; - rtpz->rb_root = RB_ROOT; - spin_lock_init(&rtpz->lock); - } - } -} - static struct cgroup_subsys_state * __ref mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) { @@ -6859,7 +6599,6 @@ static int __init mem_cgroup_init(void) { hotcpu_notifier(memcg_cpu_hotplug_callback, 0); enable_swap_cgroup(); - mem_cgroup_soft_limit_tree_init(); memcg_stock_init(); return 0; } -- cgit v1.2.3 From a5b7c87f92076352dbff2fe0423ec255e1c9a71b Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 12 Sep 2013 15:13:25 -0700 Subject: vmscan, memcg: do softlimit reclaim also for targeted reclaim Soft reclaim has been done only for the global reclaim (both background and direct). Since "memcg: integrate soft reclaim tighter with zone shrinking code" there is no reason for this limitation anymore as the soft limit reclaim doesn't use any special code paths and it is a part of the zone shrinking code which is used by both global and targeted reclaims. From the semantic point of view it is natural to consider soft limit before touching all groups in the hierarchy tree which is touching the hard limit because soft limit tells us where to push back when there is a memory pressure. It is not important whether the pressure comes from the limit or imbalanced zones. This patch simply enables soft reclaim unconditionally in mem_cgroup_should_soft_reclaim so it is enabled for both global and targeted reclaim paths. mem_cgroup_soft_reclaim_eligible needs to learn about the root of the reclaim to know where to stop checking soft limit state of parents up the hierarchy. Say we have A (over soft limit) \ B (below s.l., hit the hard limit) / \ C D (below s.l.) B is the source of the outside memory pressure now for D but we shouldn't soft reclaim it because it is behaving well under B subtree and we can still reclaim from C (pressumably it is over the limit). mem_cgroup_soft_reclaim_eligible should therefore stop climbing up the hierarchy at B (root of the memory pressure). Signed-off-by: Michal Hocko Reviewed-by: Glauber Costa Reviewed-by: Tejun Heo Cc: Balbir Singh Cc: Greg Thelen Cc: Hugh Dickins Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Michel Lespinasse Cc: Ying Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 6 ++++-- mm/memcontrol.c | 14 +++++++++----- mm/vmscan.c | 4 ++-- 3 files changed, 15 insertions(+), 9 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 4b78661c68d0..d8dd6560621b 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -180,7 +180,8 @@ static inline void mem_cgroup_dec_page_stat(struct page *page, mem_cgroup_update_page_stat(page, idx, -1); } -bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg); +bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, + struct mem_cgroup *root); void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx); static inline void mem_cgroup_count_vm_event(struct mm_struct *mm, @@ -357,7 +358,8 @@ static inline void mem_cgroup_dec_page_stat(struct page *page, } static inline -bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg) +bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, + struct mem_cgroup *root) { return false; } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 87a448dd9c10..c016e001c5b2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1773,11 +1773,13 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) #endif /* - * A group is eligible for the soft limit reclaim if it is - * a) is over its soft limit + * A group is eligible for the soft limit reclaim under the given root + * hierarchy if + * a) it is over its soft limit * b) any parent up the hierarchy is over its soft limit */ -bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg) +bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, + struct mem_cgroup *root) { struct mem_cgroup *parent = memcg; @@ -1785,12 +1787,14 @@ bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg) return true; /* - * If any parent up the hierarchy is over its soft limit then we - * have to obey and reclaim from this group as well. + * If any parent up to the root in the hierarchy is over its soft limit + * then we have to obey and reclaim from this group as well. */ while((parent = parent_mem_cgroup(parent))) { if (res_counter_soft_limit_excess(&parent->res)) return true; + if (parent == root) + break; } return false; diff --git a/mm/vmscan.c b/mm/vmscan.c index cf4643807ec2..1896e7ca494b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -142,7 +142,7 @@ static bool global_reclaim(struct scan_control *sc) static bool mem_cgroup_should_soft_reclaim(struct scan_control *sc) { - return !mem_cgroup_disabled() && global_reclaim(sc); + return !mem_cgroup_disabled(); } #else static bool global_reclaim(struct scan_control *sc) @@ -2161,7 +2161,7 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) struct lruvec *lruvec; if (soft_reclaim && - !mem_cgroup_soft_reclaim_eligible(memcg)) { + !mem_cgroup_soft_reclaim_eligible(memcg, root)) { memcg = mem_cgroup_iter(root, memcg, &reclaim); continue; } -- cgit v1.2.3 From de57780dc659f95b17ccb649f003278dde0b5b86 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 12 Sep 2013 15:13:26 -0700 Subject: memcg: enhance memcg iterator to support predicates The caller of the iterator might know that some nodes or even subtrees should be skipped but there is no way to tell iterators about that so the only choice left is to let iterators to visit each node and do the selection outside of the iterating code. This, however, doesn't scale well with hierarchies with many groups where only few groups are interesting. This patch adds mem_cgroup_iter_cond variant of the iterator with a callback which gets called for every visited node. There are three possible ways how the callback can influence the walk. Either the node is visited, it is skipped but the tree walk continues down the tree or the whole subtree of the current group is skipped. [hughd@google.com: fix memcg-less page reclaim] Signed-off-by: Michal Hocko Cc: Balbir Singh Cc: Glauber Costa Cc: Greg Thelen Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Michel Lespinasse Cc: Tejun Heo Cc: Ying Han Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 49 ++++++++++++++++++++++++++++---- mm/memcontrol.c | 70 ++++++++++++++++++++++++++++++++++++---------- mm/vmscan.c | 16 ++++------- 3 files changed, 103 insertions(+), 32 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index d8dd6560621b..d4d1f9b0dbba 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -41,6 +41,23 @@ struct mem_cgroup_reclaim_cookie { unsigned int generation; }; +enum mem_cgroup_filter_t { + VISIT, /* visit current node */ + SKIP, /* skip the current node and continue traversal */ + SKIP_TREE, /* skip the whole subtree and continue traversal */ +}; + +/* + * mem_cgroup_filter_t predicate might instruct mem_cgroup_iter_cond how to + * iterate through the hierarchy tree. Each tree element is checked by the + * predicate before it is returned by the iterator. If a filter returns + * SKIP or SKIP_TREE then the iterator code continues traversal (with the + * next node down the hierarchy or the next node that doesn't belong under the + * memcg's subtree). + */ +typedef enum mem_cgroup_filter_t +(*mem_cgroup_iter_filter)(struct mem_cgroup *memcg, struct mem_cgroup *root); + #ifdef CONFIG_MEMCG /* * All "charge" functions with gfp_mask should use GFP_KERNEL or @@ -108,9 +125,18 @@ mem_cgroup_prepare_migration(struct page *page, struct page *newpage, extern void mem_cgroup_end_migration(struct mem_cgroup *memcg, struct page *oldpage, struct page *newpage, bool migration_ok); -struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *, - struct mem_cgroup *, - struct mem_cgroup_reclaim_cookie *); +struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root, + struct mem_cgroup *prev, + struct mem_cgroup_reclaim_cookie *reclaim, + mem_cgroup_iter_filter cond); + +static inline struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, + struct mem_cgroup *prev, + struct mem_cgroup_reclaim_cookie *reclaim) +{ + return mem_cgroup_iter_cond(root, prev, reclaim, NULL); +} + void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *); /* @@ -180,7 +206,8 @@ static inline void mem_cgroup_dec_page_stat(struct page *page, mem_cgroup_update_page_stat(page, idx, -1); } -bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, +enum mem_cgroup_filter_t +mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, struct mem_cgroup *root); void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx); @@ -295,6 +322,15 @@ static inline void mem_cgroup_end_migration(struct mem_cgroup *memcg, struct page *oldpage, struct page *newpage, bool migration_ok) { } +static inline struct mem_cgroup * +mem_cgroup_iter_cond(struct mem_cgroup *root, + struct mem_cgroup *prev, + struct mem_cgroup_reclaim_cookie *reclaim, + mem_cgroup_iter_filter cond) +{ + /* first call must return non-NULL, second return NULL */ + return (struct mem_cgroup *)(unsigned long)!prev; +} static inline struct mem_cgroup * mem_cgroup_iter(struct mem_cgroup *root, @@ -358,10 +394,11 @@ static inline void mem_cgroup_dec_page_stat(struct page *page, } static inline -bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, +enum mem_cgroup_filter_t +mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, struct mem_cgroup *root) { - return false; + return VISIT; } static inline void mem_cgroup_split_huge_fixup(struct page *head) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c016e001c5b2..a4bb857d902c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -875,6 +875,15 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) return memcg; } +static enum mem_cgroup_filter_t +mem_cgroup_filter(struct mem_cgroup *memcg, struct mem_cgroup *root, + mem_cgroup_iter_filter cond) +{ + if (!cond) + return VISIT; + return cond(memcg, root); +} + /* * Returns a next (in a pre-order walk) alive memcg (with elevated css * ref. count) or NULL if the whole root's subtree has been visited. @@ -882,7 +891,7 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) * helper function to be used by mem_cgroup_iter */ static struct mem_cgroup *__mem_cgroup_iter_next(struct mem_cgroup *root, - struct mem_cgroup *last_visited) + struct mem_cgroup *last_visited, mem_cgroup_iter_filter cond) { struct cgroup_subsys_state *prev_css, *next_css; @@ -900,11 +909,31 @@ skip_node: if (next_css) { struct mem_cgroup *mem = mem_cgroup_from_css(next_css); - if (css_tryget(&mem->css)) - return mem; - else { + switch (mem_cgroup_filter(mem, root, cond)) { + case SKIP: prev_css = next_css; goto skip_node; + case SKIP_TREE: + if (mem == root) + return NULL; + /* + * css_rightmost_descendant is not an optimal way to + * skip through a subtree (especially for imbalanced + * trees leaning to right) but that's what we have right + * now. More effective solution would be traversing + * right-up for first non-NULL without calling + * css_next_descendant_pre afterwards. + */ + prev_css = css_rightmost_descendant(next_css); + goto skip_node; + case VISIT: + if (css_tryget(&mem->css)) + return mem; + else { + prev_css = next_css; + goto skip_node; + } + break; } } @@ -968,6 +997,7 @@ static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter, * @root: hierarchy root * @prev: previously returned memcg, NULL on first invocation * @reclaim: cookie for shared reclaim walks, NULL for full walks + * @cond: filter for visited nodes, NULL for no filter * * Returns references to children of the hierarchy below @root, or * @root itself, or %NULL after a full round-trip. @@ -980,15 +1010,18 @@ static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter, * divide up the memcgs in the hierarchy among all concurrent * reclaimers operating on the same zone and priority. */ -struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, +struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root, struct mem_cgroup *prev, - struct mem_cgroup_reclaim_cookie *reclaim) + struct mem_cgroup_reclaim_cookie *reclaim, + mem_cgroup_iter_filter cond) { struct mem_cgroup *memcg = NULL; struct mem_cgroup *last_visited = NULL; - if (mem_cgroup_disabled()) - return NULL; + if (mem_cgroup_disabled()) { + /* first call must return non-NULL, second return NULL */ + return (struct mem_cgroup *)(unsigned long)!prev; + } if (!root) root = root_mem_cgroup; @@ -999,7 +1032,9 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, if (!root->use_hierarchy && root != root_mem_cgroup) { if (prev) goto out_css_put; - return root; + if (mem_cgroup_filter(root, root, cond) == VISIT) + return root; + return NULL; } rcu_read_lock(); @@ -1022,7 +1057,7 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, last_visited = mem_cgroup_iter_load(iter, root, &seq); } - memcg = __mem_cgroup_iter_next(root, last_visited); + memcg = __mem_cgroup_iter_next(root, last_visited, cond); if (reclaim) { mem_cgroup_iter_update(iter, last_visited, memcg, seq); @@ -1033,7 +1068,11 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, reclaim->generation = iter->generation; } - if (prev && !memcg) + /* + * We have finished the whole tree walk or no group has been + * visited because filter told us to skip the root node. + */ + if (!memcg && (prev || (cond && !last_visited))) goto out_unlock; } out_unlock: @@ -1778,13 +1817,14 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) * a) it is over its soft limit * b) any parent up the hierarchy is over its soft limit */ -bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, +enum mem_cgroup_filter_t +mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, struct mem_cgroup *root) { struct mem_cgroup *parent = memcg; if (res_counter_soft_limit_excess(&memcg->res)) - return true; + return VISIT; /* * If any parent up to the root in the hierarchy is over its soft limit @@ -1792,12 +1832,12 @@ bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, */ while((parent = parent_mem_cgroup(parent))) { if (res_counter_soft_limit_excess(&parent->res)) - return true; + return VISIT; if (parent == root) break; } - return false; + return SKIP; } /* diff --git a/mm/vmscan.c b/mm/vmscan.c index 1896e7ca494b..f2e35099508b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2151,21 +2151,16 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) .zone = zone, .priority = sc->priority, }; - struct mem_cgroup *memcg; + struct mem_cgroup *memcg = NULL; + mem_cgroup_iter_filter filter = (soft_reclaim) ? + mem_cgroup_soft_reclaim_eligible : NULL; nr_reclaimed = sc->nr_reclaimed; nr_scanned = sc->nr_scanned; - memcg = mem_cgroup_iter(root, NULL, &reclaim); - do { + while ((memcg = mem_cgroup_iter_cond(root, memcg, &reclaim, filter))) { struct lruvec *lruvec; - if (soft_reclaim && - !mem_cgroup_soft_reclaim_eligible(memcg, root)) { - memcg = mem_cgroup_iter(root, memcg, &reclaim); - continue; - } - lruvec = mem_cgroup_zone_lruvec(zone, memcg); shrink_lruvec(lruvec, sc); @@ -2185,8 +2180,7 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) mem_cgroup_iter_break(root, memcg); break; } - memcg = mem_cgroup_iter(root, memcg, &reclaim); - } while (memcg); + } vmpressure(sc->gfp_mask, sc->target_mem_cgroup, sc->nr_scanned - nr_scanned, -- cgit v1.2.3 From 7d910c054be42515cd3e43f2e1bec8c536632de2 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 12 Sep 2013 15:13:28 -0700 Subject: memcg: track children in soft limit excess to improve soft limit Soft limit reclaim has to check the whole reclaim hierarchy while doing the first pass of the reclaim. This leads to a higher system time which can be visible especially when there are many groups in the hierarchy. This patch adds a per-memcg counter of children in excess. It also restores MEM_CGROUP_TARGET_SOFTLIMIT into mem_cgroup_event_ratelimit for a proper batching. If a group crosses soft limit for the first time it increases parent's children_in_excess up the hierarchy. The similarly if a group gets below the limit it will decrease the counter. The transition phase is recorded in soft_contributed flag. mem_cgroup_soft_reclaim_eligible then uses this information to better decide whether to skip the node or the whole subtree. The rule is simple. Skip the node with a children in excess or skip the whole subtree otherwise. This has been tested by a stream IO (dd if=/dev/zero of=file with 4*MemTotal size) which is quite sensitive to overhead during reclaim. The load is running in a group with soft limit set to 0 and without any limit. Apart from that there was a hierarchy with ~500, 2k and 8k groups (two groups on each level) without any pages in them. base denotes to the kernel on which the whole series is based on, rework is the kernel before this patch and reworkoptim is with this patch applied: * Run with soft limit set to 0 Elapsed 0-0-limit/base: min: 88.21 max: 94.61 avg: 91.73 std: 2.65 runs: 3 0-0-limit/rework: min: 76.05 [86.2%] max: 79.08 [83.6%] avg: 77.84 [84.9%] std: 1.30 runs: 3 0-0-limit/reworkoptim: min: 77.98 [88.4%] max: 80.36 [84.9%] avg: 78.92 [86.0%] std: 1.03 runs: 3 System 0.5k-0-limit/base: min: 34.86 max: 36.42 avg: 35.89 std: 0.73 runs: 3 0.5k-0-limit/rework: min: 43.26 [124.1%] max: 48.95 [134.4%] avg: 46.09 [128.4%] std: 2.32 runs: 3 0.5k-0-limit/reworkoptim: min: 46.98 [134.8%] max: 50.98 [140.0%] avg: 48.49 [135.1%] std: 1.77 runs: 3 Elapsed 0.5k-0-limit/base: min: 88.50 max: 97.52 avg: 93.92 std: 3.90 runs: 3 0.5k-0-limit/rework: min: 75.92 [85.8%] max: 78.45 [80.4%] avg: 77.34 [82.3%] std: 1.06 runs: 3 0.5k-0-limit/reworkoptim: min: 75.79 [85.6%] max: 79.37 [81.4%] avg: 77.55 [82.6%] std: 1.46 runs: 3 System 2k-0-limit/base: min: 34.57 max: 37.65 avg: 36.34 std: 1.30 runs: 3 2k-0-limit/rework: min: 64.17 [185.6%] max: 68.20 [181.1%] avg: 66.21 [182.2%] std: 1.65 runs: 3 2k-0-limit/reworkoptim: min: 49.78 [144.0%] max: 52.99 [140.7%] avg: 51.00 [140.3%] std: 1.42 runs: 3 Elapsed 2k-0-limit/base: min: 92.61 max: 97.83 avg: 95.03 std: 2.15 runs: 3 2k-0-limit/rework: min: 78.33 [84.6%] max: 84.08 [85.9%] avg: 81.09 [85.3%] std: 2.35 runs: 3 2k-0-limit/reworkoptim: min: 75.72 [81.8%] max: 78.57 [80.3%] avg: 76.73 [80.7%] std: 1.30 runs: 3 System 8k-0-limit/base: min: 39.78 max: 42.09 avg: 41.09 std: 0.97 runs: 3 8k-0-limit/rework: min: 200.86 [504.9%] max: 265.42 [630.6%] avg: 241.80 [588.5%] std: 29.06 runs: 3 8k-0-limit/reworkoptim: min: 53.70 [135.0%] max: 54.89 [130.4%] avg: 54.43 [132.5%] std: 0.52 runs: 3 Elapsed 8k-0-limit/base: min: 95.11 max: 98.61 avg: 96.81 std: 1.43 runs: 3 8k-0-limit/rework: min: 246.96 [259.7%] max: 331.47 [336.1%] avg: 301.32 [311.2%] std: 38.52 runs: 3 8k-0-limit/reworkoptim: min: 76.79 [80.7%] max: 81.71 [82.9%] avg: 78.97 [81.6%] std: 2.05 runs: 3 System time is increased by 30-40% but it is reduced a lot comparing to kernel without this patch. The higher time can be explained by the fact that the original soft reclaim scanned at priority 0 so it was much more effective for this workload (which is basically touch once and writeback). The Elapsed time looks better though (~20%). * Run with no soft limit set System 0-no-limit/base: min: 42.18 max: 50.38 avg: 46.44 std: 3.36 runs: 3 0-no-limit/rework: min: 40.57 [96.2%] max: 47.04 [93.4%] avg: 43.82 [94.4%] std: 2.64 runs: 3 0-no-limit/reworkoptim: min: 40.45 [95.9%] max: 45.28 [89.9%] avg: 42.10 [90.7%] std: 2.25 runs: 3 Elapsed 0-no-limit/base: min: 75.97 max: 78.21 avg: 76.87 std: 0.96 runs: 3 0-no-limit/rework: min: 75.59 [99.5%] max: 80.73 [103.2%] avg: 77.64 [101.0%] std: 2.23 runs: 3 0-no-limit/reworkoptim: min: 77.85 [102.5%] max: 82.42 [105.4%] avg: 79.64 [103.6%] std: 1.99 runs: 3 System 0.5k-no-limit/base: min: 44.54 max: 46.93 avg: 46.12 std: 1.12 runs: 3 0.5k-no-limit/rework: min: 42.09 [94.5%] max: 46.16 [98.4%] avg: 43.92 [95.2%] std: 1.69 runs: 3 0.5k-no-limit/reworkoptim: min: 42.47 [95.4%] max: 45.67 [97.3%] avg: 44.06 [95.5%] std: 1.31 runs: 3 Elapsed 0.5k-no-limit/base: min: 78.26 max: 81.49 avg: 79.65 std: 1.36 runs: 3 0.5k-no-limit/rework: min: 77.01 [98.4%] max: 80.43 [98.7%] avg: 78.30 [98.3%] std: 1.52 runs: 3 0.5k-no-limit/reworkoptim: min: 76.13 [97.3%] max: 77.87 [95.6%] avg: 77.18 [96.9%] std: 0.75 runs: 3 System 2k-no-limit/base: min: 62.96 max: 69.14 avg: 66.14 std: 2.53 runs: 3 2k-no-limit/rework: min: 76.01 [120.7%] max: 81.06 [117.2%] avg: 78.17 [118.2%] std: 2.12 runs: 3 2k-no-limit/reworkoptim: min: 62.57 [99.4%] max: 66.10 [95.6%] avg: 64.53 [97.6%] std: 1.47 runs: 3 Elapsed 2k-no-limit/base: min: 76.47 max: 84.22 avg: 79.12 std: 3.60 runs: 3 2k-no-limit/rework: min: 89.67 [117.3%] max: 93.26 [110.7%] avg: 91.10 [115.1%] std: 1.55 runs: 3 2k-no-limit/reworkoptim: min: 76.94 [100.6%] max: 79.21 [94.1%] avg: 78.45 [99.2%] std: 1.07 runs: 3 System 8k-no-limit/base: min: 104.74 max: 151.34 avg: 129.21 std: 19.10 runs: 3 8k-no-limit/rework: min: 205.23 [195.9%] max: 285.94 [188.9%] avg: 258.98 [200.4%] std: 38.01 runs: 3 8k-no-limit/reworkoptim: min: 161.16 [153.9%] max: 184.54 [121.9%] avg: 174.52 [135.1%] std: 9.83 runs: 3 Elapsed 8k-no-limit/base: min: 125.43 max: 181.00 avg: 154.81 std: 22.80 runs: 3 8k-no-limit/rework: min: 254.05 [202.5%] max: 355.67 [196.5%] avg: 321.46 [207.6%] std: 47.67 runs: 3 8k-no-limit/reworkoptim: min: 193.77 [154.5%] max: 222.72 [123.0%] avg: 210.18 [135.8%] std: 12.13 runs: 3 Both System and Elapsed are in stdev with the base kernel for all configurations except for 8k where both System and Elapsed are up by 35%. I do not have a good explanation for this because there is no soft reclaim pass going on as no group is above the limit which is checked in mem_cgroup_should_soft_reclaim. Then I have tested kernel build with the same configuration to see the behavior with a more general behavior. * Soft limit set to 0 for the build System 0-0-limit/base: min: 242.70 max: 245.17 avg: 243.85 std: 1.02 runs: 3 0-0-limit/rework min: 237.86 [98.0%] max: 240.22 [98.0%] avg: 239.00 [98.0%] std: 0.97 runs: 3 0-0-limit/reworkoptim: min: 241.11 [99.3%] max: 243.53 [99.3%] avg: 242.01 [99.2%] std: 1.08 runs: 3 Elapsed 0-0-limit/base: min: 348.48 max: 360.86 avg: 356.04 std: 5.41 runs: 3 0-0-limit/rework min: 286.95 [82.3%] max: 290.26 [80.4%] avg: 288.27 [81.0%] std: 1.43 runs: 3 0-0-limit/reworkoptim: min: 286.55 [82.2%] max: 289.00 [80.1%] avg: 287.69 [80.8%] std: 1.01 runs: 3 System 0.5k-0-limit/base: min: 251.77 max: 254.41 avg: 252.70 std: 1.21 runs: 3 0.5k-0-limit/rework min: 286.44 [113.8%] max: 289.30 [113.7%] avg: 287.60 [113.8%] std: 1.23 runs: 3 0.5k-0-limit/reworkoptim: min: 252.18 [100.2%] max: 253.16 [99.5%] avg: 252.62 [100.0%] std: 0.41 runs: 3 Elapsed 0.5k-0-limit/base: min: 347.83 max: 353.06 avg: 350.04 std: 2.21 runs: 3 0.5k-0-limit/rework min: 290.19 [83.4%] max: 295.62 [83.7%] avg: 293.12 [83.7%] std: 2.24 runs: 3 0.5k-0-limit/reworkoptim: min: 293.91 [84.5%] max: 294.87 [83.5%] avg: 294.29 [84.1%] std: 0.42 runs: 3 System 2k-0-limit/base: min: 263.05 max: 271.52 avg: 267.94 std: 3.58 runs: 3 2k-0-limit/rework min: 458.99 [174.5%] max: 468.31 [172.5%] avg: 464.45 [173.3%] std: 3.97 runs: 3 2k-0-limit/reworkoptim: min: 267.10 [101.5%] max: 279.38 [102.9%] avg: 272.78 [101.8%] std: 5.05 runs: 3 Elapsed 2k-0-limit/base: min: 372.33 max: 379.32 avg: 375.47 std: 2.90 runs: 3 2k-0-limit/rework min: 334.40 [89.8%] max: 339.52 [89.5%] avg: 337.44 [89.9%] std: 2.20 runs: 3 2k-0-limit/reworkoptim: min: 301.47 [81.0%] max: 319.19 [84.1%] avg: 307.90 [82.0%] std: 8.01 runs: 3 System 8k-0-limit/base: min: 320.50 max: 332.10 avg: 325.46 std: 4.88 runs: 3 8k-0-limit/rework min: 1115.76 [348.1%] max: 1165.66 [351.0%] avg: 1132.65 [348.0%] std: 23.34 runs: 3 8k-0-limit/reworkoptim: min: 403.75 [126.0%] max: 409.22 [123.2%] avg: 406.16 [124.8%] std: 2.28 runs: 3 Elapsed 8k-0-limit/base: min: 475.48 max: 585.19 avg: 525.54 std: 45.30 runs: 3 8k-0-limit/rework min: 616.25 [129.6%] max: 625.90 [107.0%] avg: 620.68 [118.1%] std: 3.98 runs: 3 8k-0-limit/reworkoptim: min: 420.18 [88.4%] max: 428.28 [73.2%] avg: 423.05 [80.5%] std: 3.71 runs: 3 Apart from 8k the system time is comparable with the base kernel while Elapsed is up to 20% better with all configurations. * No soft limit set System 0-no-limit/base: min: 234.76 max: 237.42 avg: 236.25 std: 1.11 runs: 3 0-no-limit/rework min: 233.09 [99.3%] max: 238.65 [100.5%] avg: 236.09 [99.9%] std: 2.29 runs: 3 0-no-limit/reworkoptim: min: 236.12 [100.6%] max: 240.53 [101.3%] avg: 237.94 [100.7%] std: 1.88 runs: 3 Elapsed 0-no-limit/base: min: 288.52 max: 295.42 avg: 291.29 std: 2.98 runs: 3 0-no-limit/rework min: 283.17 [98.1%] max: 284.33 [96.2%] avg: 283.78 [97.4%] std: 0.48 runs: 3 0-no-limit/reworkoptim: min: 288.50 [100.0%] max: 290.79 [98.4%] avg: 289.78 [99.5%] std: 0.95 runs: 3 System 0.5k-no-limit/base: min: 286.51 max: 293.23 avg: 290.21 std: 2.78 runs: 3 0.5k-no-limit/rework min: 291.69 [101.8%] max: 294.38 [100.4%] avg: 292.97 [101.0%] std: 1.10 runs: 3 0.5k-no-limit/reworkoptim: min: 277.05 [96.7%] max: 288.76 [98.5%] avg: 284.17 [97.9%] std: 5.11 runs: 3 Elapsed 0.5k-no-limit/base: min: 294.94 max: 298.92 avg: 296.47 std: 1.75 runs: 3 0.5k-no-limit/rework min: 292.55 [99.2%] max: 294.21 [98.4%] avg: 293.55 [99.0%] std: 0.72 runs: 3 0.5k-no-limit/reworkoptim: min: 294.41 [99.8%] max: 301.67 [100.9%] avg: 297.78 [100.4%] std: 2.99 runs: 3 System 2k-no-limit/base: min: 443.41 max: 466.66 avg: 457.66 std: 10.19 runs: 3 2k-no-limit/rework min: 490.11 [110.5%] max: 516.02 [110.6%] avg: 501.42 [109.6%] std: 10.83 runs: 3 2k-no-limit/reworkoptim: min: 435.25 [98.2%] max: 458.11 [98.2%] avg: 446.73 [97.6%] std: 9.33 runs: 3 Elapsed 2k-no-limit/base: min: 330.85 max: 333.75 avg: 332.52 std: 1.23 runs: 3 2k-no-limit/rework min: 343.06 [103.7%] max: 349.59 [104.7%] avg: 345.95 [104.0%] std: 2.72 runs: 3 2k-no-limit/reworkoptim: min: 330.01 [99.7%] max: 333.92 [100.1%] avg: 332.22 [99.9%] std: 1.64 runs: 3 System 8k-no-limit/base: min: 1175.64 max: 1259.38 avg: 1222.39 std: 34.88 runs: 3 8k-no-limit/rework min: 1226.31 [104.3%] max: 1241.60 [98.6%] avg: 1233.74 [100.9%] std: 6.25 runs: 3 8k-no-limit/reworkoptim: min: 1023.45 [87.1%] max: 1056.74 [83.9%] avg: 1038.92 [85.0%] std: 13.69 runs: 3 Elapsed 8k-no-limit/base: min: 613.36 max: 619.60 avg: 616.47 std: 2.55 runs: 3 8k-no-limit/rework min: 627.56 [102.3%] max: 642.33 [103.7%] avg: 633.44 [102.8%] std: 6.39 runs: 3 8k-no-limit/reworkoptim: min: 545.89 [89.0%] max: 555.36 [89.6%] avg: 552.06 [89.6%] std: 4.37 runs: 3 and these numbers look good as well. System time is around 100% (suprisingly better for the 8k case) and Elapsed is copies that trend. Signed-off-by: Michal Hocko Cc: Balbir Singh Cc: Glauber Costa Cc: Greg Thelen Cc: Hugh Dickins Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Michel Lespinasse Cc: Tejun Heo Cc: Ying Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index a4bb857d902c..a18e228f140b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -138,6 +138,7 @@ static const char * const mem_cgroup_lru_names[] = { */ enum mem_cgroup_events_target { MEM_CGROUP_TARGET_THRESH, + MEM_CGROUP_TARGET_SOFTLIMIT, MEM_CGROUP_TARGET_NUMAINFO, MEM_CGROUP_NTARGETS, }; @@ -315,6 +316,22 @@ struct mem_cgroup { atomic_t numainfo_events; atomic_t numainfo_updating; #endif + /* + * Protects soft_contributed transitions. + * See mem_cgroup_update_soft_limit + */ + spinlock_t soft_lock; + + /* + * If true then this group has increased parents' children_in_excess + * when it got over the soft limit. + * When a group falls bellow the soft limit, parents' children_in_excess + * is decreased and soft_contributed changed to false. + */ + bool soft_contributed; + + /* Number of children that are in soft limit excess */ + atomic_t children_in_excess; struct mem_cgroup_per_node *nodeinfo[0]; /* WARNING: nodeinfo must be the last member here */ @@ -802,6 +819,9 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, case MEM_CGROUP_TARGET_THRESH: next = val + THRESHOLDS_EVENTS_TARGET; break; + case MEM_CGROUP_TARGET_SOFTLIMIT: + next = val + SOFTLIMIT_EVENTS_TARGET; + break; case MEM_CGROUP_TARGET_NUMAINFO: next = val + NUMAINFO_EVENTS_TARGET; break; @@ -814,6 +834,42 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, return false; } +/* + * Called from rate-limitted memcg_check_events when enough + * MEM_CGROUP_TARGET_SOFTLIMIT events are accumulated and it makes sure + * that all the parents up the hierarchy will be noticed that this group + * is in excess or that it is not in excess anymore. mmecg->soft_contributed + * makes the transition a single action whenever the state flips from one to + * other. + */ +static void mem_cgroup_update_soft_limit(struct mem_cgroup *memcg) +{ + unsigned long long excess = res_counter_soft_limit_excess(&memcg->res); + struct mem_cgroup *parent = memcg; + int delta = 0; + + spin_lock(&memcg->soft_lock); + if (excess) { + if (!memcg->soft_contributed) { + delta = 1; + memcg->soft_contributed = true; + } + } else { + if (memcg->soft_contributed) { + delta = -1; + memcg->soft_contributed = false; + } + } + + /* + * Necessary to update all ancestors when hierarchy is used + * because their event counter is not touched. + */ + while (delta && (parent = parent_mem_cgroup(parent))) + atomic_add(delta, &parent->children_in_excess); + spin_unlock(&memcg->soft_lock); +} + /* * Check events in order. * @@ -824,8 +880,11 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) /* threshold event is triggered in finer grain than soft limit */ if (unlikely(mem_cgroup_event_ratelimit(memcg, MEM_CGROUP_TARGET_THRESH))) { + bool do_softlimit; bool do_numainfo __maybe_unused; + do_softlimit = mem_cgroup_event_ratelimit(memcg, + MEM_CGROUP_TARGET_SOFTLIMIT); #if MAX_NUMNODES > 1 do_numainfo = mem_cgroup_event_ratelimit(memcg, MEM_CGROUP_TARGET_NUMAINFO); @@ -833,6 +892,8 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) preempt_enable(); mem_cgroup_threshold(memcg); + if (unlikely(do_softlimit)) + mem_cgroup_update_soft_limit(memcg); #if MAX_NUMNODES > 1 if (unlikely(do_numainfo)) atomic_inc(&memcg->numainfo_events); @@ -1816,6 +1877,9 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) * hierarchy if * a) it is over its soft limit * b) any parent up the hierarchy is over its soft limit + * + * If the given group doesn't have any children over the limit then it + * doesn't make any sense to iterate its subtree. */ enum mem_cgroup_filter_t mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, @@ -1837,6 +1901,8 @@ mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, break; } + if (!atomic_read(&memcg->children_in_excess)) + return SKIP_TREE; return SKIP; } @@ -5892,6 +5958,7 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) mutex_init(&memcg->thresholds_lock); spin_lock_init(&memcg->move_lock); vmpressure_init(&memcg->vmpressure); + spin_lock_init(&memcg->soft_lock); return &memcg->css; @@ -5969,6 +6036,10 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) mem_cgroup_invalidate_reclaim_iterators(memcg); mem_cgroup_reparent_charges(memcg); + if (memcg->soft_contributed) { + while ((memcg = parent_mem_cgroup(memcg))) + atomic_dec(&memcg->children_in_excess); + } mem_cgroup_destroy_all_caches(memcg); vmpressure_cleanup(&memcg->vmpressure); } -- cgit v1.2.3 From e839b6a1c8d0895803bcbd587595a54f4221a625 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 12 Sep 2013 15:13:30 -0700 Subject: memcg, vmscan: do not attempt soft limit reclaim if it would not scan anything mem_cgroup_should_soft_reclaim controls whether soft reclaim pass is done and it always says yes currently. Memcg iterators are clever to skip nodes that are not soft reclaimable quite efficiently but mem_cgroup_should_soft_reclaim can be more clever and do not start the soft reclaim pass at all if it knows that nothing would be scanned anyway. In order to do that, simply reuse mem_cgroup_soft_reclaim_eligible for the target group of the reclaim and allow the pass only if the whole subtree wouldn't be skipped. Signed-off-by: Michal Hocko Cc: Balbir Singh Cc: Glauber Costa Cc: Greg Thelen Cc: Hugh Dickins Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Michel Lespinasse Cc: Tejun Heo Cc: Ying Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 6 +++++- mm/vmscan.c | 4 +++- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index a18e228f140b..848fc6c195d2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1885,7 +1885,11 @@ enum mem_cgroup_filter_t mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, struct mem_cgroup *root) { - struct mem_cgroup *parent = memcg; + struct mem_cgroup *parent; + + if (!memcg) + memcg = root_mem_cgroup; + parent = memcg; if (res_counter_soft_limit_excess(&memcg->res)) return VISIT; diff --git a/mm/vmscan.c b/mm/vmscan.c index f2e35099508b..04dca89c4f34 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -142,7 +142,9 @@ static bool global_reclaim(struct scan_control *sc) static bool mem_cgroup_should_soft_reclaim(struct scan_control *sc) { - return !mem_cgroup_disabled(); + struct mem_cgroup *root = sc->target_mem_cgroup; + return !mem_cgroup_disabled() && + mem_cgroup_soft_reclaim_eligible(root, root) != SKIP_TREE; } #else static bool global_reclaim(struct scan_control *sc) -- cgit v1.2.3 From 1be171d60bddcce2602c5d009029274d67736fd7 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 12 Sep 2013 15:13:32 -0700 Subject: memcg: track all children over limit in the root Children in soft limit excess are currently tracked up the hierarchy in memcg->children_in_excess. Nevertheless there still might exist tons of groups that are not in hierarchy relation to the root cgroup (e.g. all first level groups if root_mem_cgroup->use_hierarchy == false). As the whole tree walk has to be done when the iteration starts at root_mem_cgroup the iterator should be able to skip the walk if there is no child above the limit without iterating them. This can be done easily if the root tracks all children rather than only hierarchical children. This is done by this patch which updates root_mem_cgroup children_in_excess if root_mem_cgroup->use_hierarchy == false so the root knows about all children in excess. Please note that this is not an issue for inner memcgs which have use_hierarchy == false because then only the single group is visited so no special optimization is necessary. Signed-off-by: Michal Hocko Cc: Balbir Singh Cc: Glauber Costa Cc: Greg Thelen Cc: Hugh Dickins Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Michel Lespinasse Cc: Tejun Heo Cc: Ying Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 848fc6c195d2..46717d6c62b7 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -864,9 +864,15 @@ static void mem_cgroup_update_soft_limit(struct mem_cgroup *memcg) /* * Necessary to update all ancestors when hierarchy is used * because their event counter is not touched. + * We track children even outside the hierarchy for the root + * cgroup because tree walk starting at root should visit + * all cgroups and we want to prevent from pointless tree + * walk if no children is below the limit. */ while (delta && (parent = parent_mem_cgroup(parent))) atomic_add(delta, &parent->children_in_excess); + if (memcg != root_mem_cgroup && !root_mem_cgroup->use_hierarchy) + atomic_add(delta, &root_mem_cgroup->children_in_excess); spin_unlock(&memcg->soft_lock); } @@ -6043,6 +6049,9 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) if (memcg->soft_contributed) { while ((memcg = parent_mem_cgroup(memcg))) atomic_dec(&memcg->children_in_excess); + + if (memcg != root_mem_cgroup && !root_mem_cgroup->use_hierarchy) + atomic_dec(&root_mem_cgroup->children_in_excess); } mem_cgroup_destroy_all_caches(memcg); vmpressure_cleanup(&memcg->vmpressure); -- cgit v1.2.3 From e975de998b9612aa97e3165f8827c09e0d36ce77 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 12 Sep 2013 15:13:34 -0700 Subject: memcg, vmscan: do not fall into reclaim-all pass too quickly shrink_zone starts with soft reclaim pass first and then falls back to regular reclaim if nothing has been scanned. This behavior is natural but there is a catch. Memcg iterators, when used with the reclaim cookie, are designed to help to prevent from over reclaim by interleaving reclaimers (per node-zone-priority) so the tree walk might miss many (even all) nodes in the hierarchy e.g. when there are direct reclaimers racing with each other or with kswapd in the global case or multiple allocators reaching the limit for the target reclaim case. To make it even more complicated, targeted reclaim doesn't do the whole tree walk because it stops reclaiming once it reclaims sufficient pages. As a result groups over the limit might be missed, thus nothing is scanned, and reclaim would fall back to the reclaim all mode. This patch checks for the incomplete tree walk in shrink_zone. If no group has been visited and the hierarchy is soft reclaimable then we must have missed some groups, in which case the __shrink_zone is called again. This doesn't guarantee there will be some progress of course because the current reclaimer might be still racing with others but it would at least give a chance to start the walk without a big risk of reclaim latencies. Signed-off-by: Michal Hocko Cc: Balbir Singh Cc: Glauber Costa Cc: Greg Thelen Cc: Hugh Dickins Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Michel Lespinasse Cc: Tejun Heo Cc: Ying Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 04dca89c4f34..fa91c20fe4b7 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2142,10 +2142,11 @@ static inline bool should_continue_reclaim(struct zone *zone, } } -static void +static int __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) { unsigned long nr_reclaimed, nr_scanned; + int groups_scanned = 0; do { struct mem_cgroup *root = sc->target_mem_cgroup; @@ -2163,6 +2164,7 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) while ((memcg = mem_cgroup_iter_cond(root, memcg, &reclaim, filter))) { struct lruvec *lruvec; + groups_scanned++; lruvec = mem_cgroup_zone_lruvec(zone, memcg); shrink_lruvec(lruvec, sc); @@ -2190,6 +2192,8 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) } while (should_continue_reclaim(zone, sc->nr_reclaimed - nr_reclaimed, sc->nr_scanned - nr_scanned, sc)); + + return groups_scanned; } @@ -2197,8 +2201,19 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc) { bool do_soft_reclaim = mem_cgroup_should_soft_reclaim(sc); unsigned long nr_scanned = sc->nr_scanned; + int scanned_groups; - __shrink_zone(zone, sc, do_soft_reclaim); + scanned_groups = __shrink_zone(zone, sc, do_soft_reclaim); + /* + * memcg iterator might race with other reclaimer or start from + * a incomplete tree walk so the tree walk in __shrink_zone + * might have missed groups that are above the soft limit. Try + * another loop to catch up with others. Do it just once to + * prevent from reclaim latencies when other reclaimers always + * preempt this one. + */ + if (do_soft_reclaim && !scanned_groups) + __shrink_zone(zone, sc, do_soft_reclaim); /* * No group is over the soft limit or those that are do not have -- cgit v1.2.3 From f894ffa865301d4010d68b15be29912fa4039e77 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Thu, 12 Sep 2013 15:13:35 -0700 Subject: memcg: trivial cleanups Clean up some mess made by the "Soft limit rework" series, and a few other things. Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 30 +++++++++++++++--------------- mm/vmscan.c | 12 ++++++------ 2 files changed, 21 insertions(+), 21 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 46717d6c62b7..c4524458b7d0 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -279,7 +279,7 @@ struct mem_cgroup { * Should we move charges of a task when a task is moved into this * mem_cgroup ? And what type of charges should we move ? */ - unsigned long move_charge_at_immigrate; + unsigned long move_charge_at_immigrate; /* * set > 0 if pages under this cgroup are moving to other cgroup. */ @@ -324,7 +324,7 @@ struct mem_cgroup { /* * If true then this group has increased parents' children_in_excess - * when it got over the soft limit. + * when it got over the soft limit. * When a group falls bellow the soft limit, parents' children_in_excess * is decreased and soft_contributed changed to false. */ @@ -835,12 +835,12 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, } /* - * Called from rate-limitted memcg_check_events when enough + * Called from rate-limited memcg_check_events when enough * MEM_CGROUP_TARGET_SOFTLIMIT events are accumulated and it makes sure - * that all the parents up the hierarchy will be noticed that this group + * that all the parents up the hierarchy will be notified that this group * is in excess or that it is not in excess anymore. mmecg->soft_contributed * makes the transition a single action whenever the state flips from one to - * other. + * the other. */ static void mem_cgroup_update_soft_limit(struct mem_cgroup *memcg) { @@ -1881,8 +1881,8 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) /* * A group is eligible for the soft limit reclaim under the given root * hierarchy if - * a) it is over its soft limit - * b) any parent up the hierarchy is over its soft limit + * a) it is over its soft limit + * b) any parent up the hierarchy is over its soft limit * * If the given group doesn't have any children over the limit then it * doesn't make any sense to iterate its subtree. @@ -1904,7 +1904,7 @@ mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, * If any parent up to the root in the hierarchy is over its soft limit * then we have to obey and reclaim from this group as well. */ - while((parent = parent_mem_cgroup(parent))) { + while ((parent = parent_mem_cgroup(parent))) { if (res_counter_soft_limit_excess(&parent->res)) return VISIT; if (parent == root) @@ -2309,7 +2309,7 @@ static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) flush_work(&stock->work); } out: - put_online_cpus(); + put_online_cpus(); } /* @@ -2741,7 +2741,7 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, * is accessed after testing USED bit. To make pc->mem_cgroup visible * before USED bit, we need memory barrier here. * See mem_cgroup_add_lru_list(), etc. - */ + */ smp_wmb(); SetPageCgroupUsed(pc); @@ -3483,9 +3483,9 @@ __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) * the page allocator. Therefore, the following sequence when backed by * the SLUB allocator: * - * memcg_stop_kmem_account(); - * kmalloc() - * memcg_resume_kmem_account(); + * memcg_stop_kmem_account(); + * kmalloc() + * memcg_resume_kmem_account(); * * would effectively ignore the fact that we should skip accounting, * since it will drive us directly to this function without passing @@ -4514,7 +4514,7 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, MEM_CGROUP_RECLAIM_SHRINK); curusage = res_counter_read_u64(&memcg->res, RES_USAGE); /* Usage is reduced ? */ - if (curusage >= oldusage) + if (curusage >= oldusage) retry_count--; else oldusage = curusage; @@ -4535,7 +4535,7 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, int enlarge = 0; /* see mem_cgroup_resize_res_limit */ - retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; + retry_count = children * MEM_CGROUP_RECLAIM_RETRIES; oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE); while (retry_count) { if (signal_pending(current)) { diff --git a/mm/vmscan.c b/mm/vmscan.c index fa91c20fe4b7..76d1d5eaeec3 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2205,12 +2205,12 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc) scanned_groups = __shrink_zone(zone, sc, do_soft_reclaim); /* - * memcg iterator might race with other reclaimer or start from - * a incomplete tree walk so the tree walk in __shrink_zone - * might have missed groups that are above the soft limit. Try - * another loop to catch up with others. Do it just once to - * prevent from reclaim latencies when other reclaimers always - * preempt this one. + * memcg iterator might race with other reclaimer or start from + * a incomplete tree walk so the tree walk in __shrink_zone + * might have missed groups that are above the soft limit. Try + * another loop to catch up with others. Do it just once to + * prevent from reclaim latencies when other reclaimers always + * preempt this one. */ if (do_soft_reclaim && !scanned_groups) __shrink_zone(zone, sc, do_soft_reclaim); -- cgit v1.2.3 From 94bce453c78996cc4373d5da6cfabe07fcc6d9f9 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 12 Sep 2013 15:13:36 -0700 Subject: arch: mm: remove obsolete init OOM protection The memcg code can trap tasks in the context of the failing allocation until an OOM situation is resolved. They can hold all kinds of locks (fs, mm) at this point, which makes it prone to deadlocking. This series converts memcg OOM handling into a two step process that is started in the charge context, but any waiting is done after the fault stack is fully unwound. Patches 1-4 prepare architecture handlers to support the new memcg requirements, but in doing so they also remove old cruft and unify out-of-memory behavior across architectures. Patch 5 disables the memcg OOM handling for syscalls, readahead, kernel faults, because they can gracefully unwind the stack with -ENOMEM. OOM handling is restricted to user triggered faults that have no other option. Patch 6 reworks memcg's hierarchical OOM locking to make it a little more obvious wth is going on in there: reduce locked regions, rename locking functions, reorder and document. Patch 7 implements the two-part OOM handling such that tasks are never trapped with the full charge stack in an OOM situation. This patch: Back before smart OOM killing, when faulting tasks were killed directly on allocation failures, the arch-specific fault handlers needed special protection for the init process. Now that all fault handlers call into the generic OOM killer (see commit 609838cfed97: "mm: invoke oom-killer from remaining unconverted page fault handlers"), which already provides init protection, the arch-specific leftovers can be removed. Signed-off-by: Johannes Weiner Reviewed-by: Michal Hocko Acked-by: KOSAKI Motohiro Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: azurIt Acked-by: Vineet Gupta [arch/arc bits] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arc/mm/fault.c | 5 ----- arch/score/mm/fault.c | 6 ------ arch/tile/mm/fault.c | 6 ------ 3 files changed, 17 deletions(-) diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c index 0fd1f0d515ff..6b0bb415af40 100644 --- a/arch/arc/mm/fault.c +++ b/arch/arc/mm/fault.c @@ -122,7 +122,6 @@ good_area: goto bad_area; } -survive: /* * If for any reason at all we couldn't handle the fault, * make sure we exit gracefully rather than endlessly redo @@ -201,10 +200,6 @@ no_context: die("Oops", regs, address); out_of_memory: - if (is_global_init(tsk)) { - yield(); - goto survive; - } up_read(&mm->mmap_sem); if (user_mode(regs)) { diff --git a/arch/score/mm/fault.c b/arch/score/mm/fault.c index 6b18fb0189ae..4b71a626d41e 100644 --- a/arch/score/mm/fault.c +++ b/arch/score/mm/fault.c @@ -100,7 +100,6 @@ good_area: goto bad_area; } -survive: /* * If for any reason at all we couldn't handle the fault, * make sure we exit gracefully rather than endlessly redo @@ -167,11 +166,6 @@ no_context: */ out_of_memory: up_read(&mm->mmap_sem); - if (is_global_init(tsk)) { - yield(); - down_read(&mm->mmap_sem); - goto survive; - } if (!user_mode(regs)) goto no_context; pagefault_out_of_memory(); diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c index 111d5a9b76f1..4fd2c0f2a66d 100644 --- a/arch/tile/mm/fault.c +++ b/arch/tile/mm/fault.c @@ -430,7 +430,6 @@ good_area: goto bad_area; } - survive: /* * If for any reason at all we couldn't handle the fault, * make sure we exit gracefully rather than endlessly redo @@ -555,11 +554,6 @@ no_context: */ out_of_memory: up_read(&mm->mmap_sem); - if (is_global_init(tsk)) { - yield(); - down_read(&mm->mmap_sem); - goto survive; - } if (is_kernel_mode) goto no_context; pagefault_out_of_memory(); -- cgit v1.2.3 From 871341023c771ad233620b7a1fb3d9c7031c4e5c Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 12 Sep 2013 15:13:38 -0700 Subject: arch: mm: do not invoke OOM killer on kernel fault OOM Kernel faults are expected to handle OOM conditions gracefully (gup, uaccess etc.), so they should never invoke the OOM killer. Reserve this for faults triggered in user context when it is the only option. Most architectures already do this, fix up the remaining few. Signed-off-by: Johannes Weiner Reviewed-by: Michal Hocko Acked-by: KOSAKI Motohiro Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: azurIt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm/mm/fault.c | 14 +++++++------- arch/arm64/mm/fault.c | 14 +++++++------- arch/avr32/mm/fault.c | 2 +- arch/mips/mm/fault.c | 2 ++ arch/um/kernel/trap.c | 2 ++ arch/unicore32/mm/fault.c | 14 +++++++------- 6 files changed, 26 insertions(+), 22 deletions(-) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index c97f7940cb95..217bcbfde42e 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -349,6 +349,13 @@ retry: if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS)))) return 0; + /* + * If we are in kernel mode at this point, we + * have no context to handle this fault with. + */ + if (!user_mode(regs)) + goto no_context; + if (fault & VM_FAULT_OOM) { /* * We ran out of memory, call the OOM killer, and return to @@ -359,13 +366,6 @@ retry: return 0; } - /* - * If we are in kernel mode at this point, we - * have no context to handle this fault with. - */ - if (!user_mode(regs)) - goto no_context; - if (fault & VM_FAULT_SIGBUS) { /* * We had some memory, but were unable to diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 6c8ba25bf6bb..0bb7db41f4fe 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -288,6 +288,13 @@ retry: VM_FAULT_BADACCESS)))) return 0; + /* + * If we are in kernel mode at this point, we have no context to + * handle this fault with. + */ + if (!user_mode(regs)) + goto no_context; + if (fault & VM_FAULT_OOM) { /* * We ran out of memory, call the OOM killer, and return to @@ -298,13 +305,6 @@ retry: return 0; } - /* - * If we are in kernel mode at this point, we have no context to - * handle this fault with. - */ - if (!user_mode(regs)) - goto no_context; - if (fault & VM_FAULT_SIGBUS) { /* * We had some memory, but were unable to successfully fix up diff --git a/arch/avr32/mm/fault.c b/arch/avr32/mm/fault.c index b2f2d2d66849..2ca27b055825 100644 --- a/arch/avr32/mm/fault.c +++ b/arch/avr32/mm/fault.c @@ -228,9 +228,9 @@ no_context: */ out_of_memory: up_read(&mm->mmap_sem); - pagefault_out_of_memory(); if (!user_mode(regs)) goto no_context; + pagefault_out_of_memory(); return; do_sigbus: diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c index 85df1cd8d446..94d3a31ab144 100644 --- a/arch/mips/mm/fault.c +++ b/arch/mips/mm/fault.c @@ -241,6 +241,8 @@ out_of_memory: * (which will retry the fault, or kill us if we got oom-killed). */ up_read(&mm->mmap_sem); + if (!user_mode(regs)) + goto no_context; pagefault_out_of_memory(); return; diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c index 089f3987e273..b2f5adf838dd 100644 --- a/arch/um/kernel/trap.c +++ b/arch/um/kernel/trap.c @@ -124,6 +124,8 @@ out_of_memory: * (which will retry the fault, or kill us if we got oom-killed). */ up_read(&mm->mmap_sem); + if (!is_user) + goto out_nosemaphore; pagefault_out_of_memory(); return 0; } diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c index f9b5c10bccee..8ed3c4509d84 100644 --- a/arch/unicore32/mm/fault.c +++ b/arch/unicore32/mm/fault.c @@ -278,6 +278,13 @@ retry: (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS)))) return 0; + /* + * If we are in kernel mode at this point, we + * have no context to handle this fault with. + */ + if (!user_mode(regs)) + goto no_context; + if (fault & VM_FAULT_OOM) { /* * We ran out of memory, call the OOM killer, and return to @@ -288,13 +295,6 @@ retry: return 0; } - /* - * If we are in kernel mode at this point, we - * have no context to handle this fault with. - */ - if (!user_mode(regs)) - goto no_context; - if (fault & VM_FAULT_SIGBUS) { /* * We had some memory, but were unable to -- cgit v1.2.3 From 759496ba6407c6994d6a5ce3a5e74937d7816208 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 12 Sep 2013 15:13:39 -0700 Subject: arch: mm: pass userspace fault flag to generic fault handler Unlike global OOM handling, memory cgroup code will invoke the OOM killer in any OOM situation because it has no way of telling faults occuring in kernel context - which could be handled more gracefully - from user-triggered faults. Pass a flag that identifies faults originating in user space from the architecture-specific fault handlers to generic code so that memcg OOM handling can be improved. Signed-off-by: Johannes Weiner Reviewed-by: Michal Hocko Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: azurIt Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/alpha/mm/fault.c | 7 ++++--- arch/arc/mm/fault.c | 6 ++++-- arch/arm/mm/fault.c | 9 ++++++--- arch/arm64/mm/fault.c | 17 ++++++++++------- arch/avr32/mm/fault.c | 2 ++ arch/cris/mm/fault.c | 6 ++++-- arch/frv/mm/fault.c | 10 ++++++---- arch/hexagon/mm/vm_fault.c | 6 ++++-- arch/ia64/mm/fault.c | 6 ++++-- arch/m32r/mm/fault.c | 10 ++++++---- arch/m68k/mm/fault.c | 2 ++ arch/metag/mm/fault.c | 6 ++++-- arch/microblaze/mm/fault.c | 7 +++++-- arch/mips/mm/fault.c | 6 ++++-- arch/mn10300/mm/fault.c | 2 ++ arch/openrisc/mm/fault.c | 1 + arch/parisc/mm/fault.c | 7 +++++-- arch/powerpc/mm/fault.c | 7 ++++--- arch/s390/mm/fault.c | 2 ++ arch/score/mm/fault.c | 7 ++++++- arch/sh/mm/fault.c | 9 ++++++--- arch/sparc/mm/fault_32.c | 12 +++++++++--- arch/sparc/mm/fault_64.c | 6 ++++-- arch/tile/mm/fault.c | 7 +++++-- arch/um/kernel/trap.c | 20 ++++++++++++-------- arch/unicore32/mm/fault.c | 8 ++++++-- arch/x86/mm/fault.c | 8 +++++--- arch/xtensa/mm/fault.c | 2 ++ include/linux/mm.h | 1 + 29 files changed, 135 insertions(+), 64 deletions(-) diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c index 0c4132dd3507..98838a05ba6d 100644 --- a/arch/alpha/mm/fault.c +++ b/arch/alpha/mm/fault.c @@ -89,8 +89,7 @@ do_page_fault(unsigned long address, unsigned long mmcsr, const struct exception_table_entry *fixup; int fault, si_code = SEGV_MAPERR; siginfo_t info; - unsigned int flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (cause > 0 ? FAULT_FLAG_WRITE : 0)); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; /* As of EV6, a load into $31/$f31 is a prefetch, and never faults (or is suppressed by the PALcode). Support that for older CPUs @@ -115,7 +114,8 @@ do_page_fault(unsigned long address, unsigned long mmcsr, if (address >= TASK_SIZE) goto vmalloc_fault; #endif - + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -142,6 +142,7 @@ retry: } else { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } /* If for any reason at all we couldn't handle the fault, diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c index 6b0bb415af40..d63f3de0cd5b 100644 --- a/arch/arc/mm/fault.c +++ b/arch/arc/mm/fault.c @@ -60,8 +60,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address) siginfo_t info; int fault, ret; int write = regs->ecr_cause & ECR_C_PROTV_STORE; /* ST/EX */ - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; /* * We fault-in kernel-space virtual memory on-demand. The @@ -89,6 +88,8 @@ void do_page_fault(struct pt_regs *regs, unsigned long address) if (in_atomic() || !mm) goto no_context; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -117,6 +118,7 @@ good_area: if (write) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } else { if (!(vma->vm_flags & (VM_READ | VM_EXEC))) goto bad_area; diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 217bcbfde42e..eb8830a4c5ed 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -261,9 +261,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) struct task_struct *tsk; struct mm_struct *mm; int fault, sig, code; - int write = fsr & FSR_WRITE; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; if (notify_page_fault(regs, fsr)) return 0; @@ -282,6 +280,11 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (in_atomic() || !mm) goto no_context; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + if (fsr & FSR_WRITE) + flags |= FAULT_FLAG_WRITE; + /* * As per x86, we may deadlock here. However, since the kernel only * validly references user space from well defined areas of the code, diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 0bb7db41f4fe..6d6acf153bff 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -199,13 +199,6 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC; unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; - if (esr & ESR_LNX_EXEC) { - vm_flags = VM_EXEC; - } else if ((esr & ESR_WRITE) && !(esr & ESR_CM)) { - vm_flags = VM_WRITE; - mm_flags |= FAULT_FLAG_WRITE; - } - tsk = current; mm = tsk->mm; @@ -220,6 +213,16 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, if (in_atomic() || !mm) goto no_context; + if (user_mode(regs)) + mm_flags |= FAULT_FLAG_USER; + + if (esr & ESR_LNX_EXEC) { + vm_flags = VM_EXEC; + } else if ((esr & ESR_WRITE) && !(esr & ESR_CM)) { + vm_flags = VM_WRITE; + mm_flags |= FAULT_FLAG_WRITE; + } + /* * As per x86, we may deadlock here. However, since the kernel only * validly references user space from well defined areas of the code, diff --git a/arch/avr32/mm/fault.c b/arch/avr32/mm/fault.c index 2ca27b055825..0eca93327195 100644 --- a/arch/avr32/mm/fault.c +++ b/arch/avr32/mm/fault.c @@ -86,6 +86,8 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs) local_irq_enable(); + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); diff --git a/arch/cris/mm/fault.c b/arch/cris/mm/fault.c index 73312ab6c696..1790f22e71a2 100644 --- a/arch/cris/mm/fault.c +++ b/arch/cris/mm/fault.c @@ -58,8 +58,7 @@ do_page_fault(unsigned long address, struct pt_regs *regs, struct vm_area_struct * vma; siginfo_t info; int fault; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - ((writeaccess & 1) ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; D(printk(KERN_DEBUG "Page fault for %lX on %X at %lX, prot %d write %d\n", @@ -117,6 +116,8 @@ do_page_fault(unsigned long address, struct pt_regs *regs, if (in_atomic() || !mm) goto no_context; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -155,6 +156,7 @@ retry: } else if (writeaccess == 1) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } else { if (!(vma->vm_flags & (VM_READ | VM_EXEC))) goto bad_area; diff --git a/arch/frv/mm/fault.c b/arch/frv/mm/fault.c index 331c1e2cfb67..9a66372fc7c7 100644 --- a/arch/frv/mm/fault.c +++ b/arch/frv/mm/fault.c @@ -34,11 +34,11 @@ asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear struct vm_area_struct *vma; struct mm_struct *mm; unsigned long _pme, lrai, lrad, fixup; + unsigned long flags = 0; siginfo_t info; pgd_t *pge; pud_t *pue; pte_t *pte; - int write; int fault; #if 0 @@ -81,6 +81,9 @@ asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear if (in_atomic() || !mm) goto no_context; + if (user_mode(__frame)) + flags |= FAULT_FLAG_USER; + down_read(&mm->mmap_sem); vma = find_vma(mm, ear0); @@ -129,7 +132,6 @@ asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear */ good_area: info.si_code = SEGV_ACCERR; - write = 0; switch (esr0 & ESR0_ATXC) { default: /* handle write to write protected page */ @@ -140,7 +142,7 @@ asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear #endif if (!(vma->vm_flags & VM_WRITE)) goto bad_area; - write = 1; + flags |= FAULT_FLAG_WRITE; break; /* handle read from protected page */ @@ -162,7 +164,7 @@ asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear * make sure we exit gracefully rather than endlessly redo * the fault. */ - fault = handle_mm_fault(mm, vma, ear0, write ? FAULT_FLAG_WRITE : 0); + fault = handle_mm_fault(mm, vma, ear0, flags); if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c index 1bd276dbec7d..8704c9320032 100644 --- a/arch/hexagon/mm/vm_fault.c +++ b/arch/hexagon/mm/vm_fault.c @@ -53,8 +53,7 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs) int si_code = SEGV_MAPERR; int fault; const struct exception_table_entry *fixup; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (cause > 0 ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; /* * If we're in an interrupt or have no user context, @@ -65,6 +64,8 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs) local_irq_enable(); + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -96,6 +97,7 @@ good_area: case FLT_STORE: if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; break; } diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c index 6cf0341f978e..7225dad87094 100644 --- a/arch/ia64/mm/fault.c +++ b/arch/ia64/mm/fault.c @@ -90,8 +90,6 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re mask = ((((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT) | (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT)); - flags |= ((mask & VM_WRITE) ? FAULT_FLAG_WRITE : 0); - /* mmap_sem is performance critical.... */ prefetchw(&mm->mmap_sem); @@ -119,6 +117,10 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re if (notify_page_fault(regs, TRAP_BRKPT)) return; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + if (mask & VM_WRITE) + flags |= FAULT_FLAG_WRITE; retry: down_read(&mm->mmap_sem); diff --git a/arch/m32r/mm/fault.c b/arch/m32r/mm/fault.c index 3cdfa9c1d091..e9c6a8014bd6 100644 --- a/arch/m32r/mm/fault.c +++ b/arch/m32r/mm/fault.c @@ -78,7 +78,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code, struct mm_struct *mm; struct vm_area_struct * vma; unsigned long page, addr; - int write; + unsigned long flags = 0; int fault; siginfo_t info; @@ -117,6 +117,9 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code, if (in_atomic() || !mm) goto bad_area_nosemaphore; + if (error_code & ACE_USERMODE) + flags |= FAULT_FLAG_USER; + /* When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in the * kernel and should generate an OOPS. Unfortunately, in the case of an @@ -166,14 +169,13 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code, */ good_area: info.si_code = SEGV_ACCERR; - write = 0; switch (error_code & (ACE_WRITE|ACE_PROTECTION)) { default: /* 3: write, present */ /* fall through */ case ACE_WRITE: /* write, not present */ if (!(vma->vm_flags & VM_WRITE)) goto bad_area; - write++; + flags |= FAULT_FLAG_WRITE; break; case ACE_PROTECTION: /* read, present */ case 0: /* read, not present */ @@ -194,7 +196,7 @@ good_area: */ addr = (address & PAGE_MASK); set_thread_fault_code(error_code); - fault = handle_mm_fault(mm, vma, addr, write ? FAULT_FLAG_WRITE : 0); + fault = handle_mm_fault(mm, vma, addr, flags); if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c index a563727806bf..eb1d61f68725 100644 --- a/arch/m68k/mm/fault.c +++ b/arch/m68k/mm/fault.c @@ -88,6 +88,8 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, if (in_atomic() || !mm) goto no_context; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); diff --git a/arch/metag/mm/fault.c b/arch/metag/mm/fault.c index 8fddf46e6c62..332680e5ebf2 100644 --- a/arch/metag/mm/fault.c +++ b/arch/metag/mm/fault.c @@ -53,8 +53,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, struct vm_area_struct *vma, *prev_vma; siginfo_t info; int fault; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write_access ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; tsk = current; @@ -109,6 +108,8 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, if (in_atomic() || !mm) goto no_context; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); @@ -121,6 +122,7 @@ good_area: if (write_access) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } else { if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) goto bad_area; diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c index 731f739d17a1..fa4cf52aa7a6 100644 --- a/arch/microblaze/mm/fault.c +++ b/arch/microblaze/mm/fault.c @@ -92,8 +92,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address, int code = SEGV_MAPERR; int is_write = error_code & ESR_S; int fault; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (is_write ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; regs->ear = address; regs->esr = error_code; @@ -121,6 +120,9 @@ void do_page_fault(struct pt_regs *regs, unsigned long address, die("Weird page fault", regs, SIGSEGV); } + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + /* When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in the * kernel and should generate an OOPS. Unfortunately, in the case of an @@ -199,6 +201,7 @@ good_area: if (unlikely(is_write)) { if (unlikely(!(vma->vm_flags & VM_WRITE))) goto bad_area; + flags |= FAULT_FLAG_WRITE; /* a read */ } else { /* protection fault */ diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c index 94d3a31ab144..becc42bb1849 100644 --- a/arch/mips/mm/fault.c +++ b/arch/mips/mm/fault.c @@ -42,8 +42,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write, const int field = sizeof(unsigned long) * 2; siginfo_t info; int fault; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; #if 0 printk("Cpu%d[%s:%d:%0*lx:%ld:%0*lx]\n", raw_smp_processor_id(), @@ -93,6 +92,8 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write, if (in_atomic() || !mm) goto bad_area_nosemaphore; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -114,6 +115,7 @@ good_area: if (write) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } else { if (cpu_has_rixi) { if (address == regs->cp0_epc && !(vma->vm_flags & VM_EXEC)) { diff --git a/arch/mn10300/mm/fault.c b/arch/mn10300/mm/fault.c index 8a2e6ded9a44..3516cbdf1ee9 100644 --- a/arch/mn10300/mm/fault.c +++ b/arch/mn10300/mm/fault.c @@ -171,6 +171,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long fault_code, if (in_atomic() || !mm) goto no_context; + if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c index 4a41f8493ab0..0703acf7d327 100644 --- a/arch/openrisc/mm/fault.c +++ b/arch/openrisc/mm/fault.c @@ -86,6 +86,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, if (user_mode(regs)) { /* Exception was in userspace: reenable interrupts */ local_irq_enable(); + flags |= FAULT_FLAG_USER; } else { /* If exception was in a syscall, then IRQ's may have * been enabled or disabled. If they were enabled, diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c index f247a3480e8e..d10d27a720c0 100644 --- a/arch/parisc/mm/fault.c +++ b/arch/parisc/mm/fault.c @@ -180,6 +180,10 @@ void do_page_fault(struct pt_regs *regs, unsigned long code, if (in_atomic() || !mm) goto no_context; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + if (acc_type & VM_WRITE) + flags |= FAULT_FLAG_WRITE; retry: down_read(&mm->mmap_sem); vma = find_vma_prev(mm, address, &prev_vma); @@ -203,8 +207,7 @@ good_area: * fault. */ - fault = handle_mm_fault(mm, vma, address, - flags | ((acc_type & VM_WRITE) ? FAULT_FLAG_WRITE : 0)); + fault = handle_mm_fault(mm, vma, address, flags); if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) return; diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 2dd69bf4af46..51ab9e7e6c39 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -223,9 +223,6 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address, is_write = error_code & ESR_DST; #endif /* CONFIG_4xx || CONFIG_BOOKE */ - if (is_write) - flags |= FAULT_FLAG_WRITE; - #ifdef CONFIG_PPC_ICSWX /* * we need to do this early because this "data storage @@ -288,6 +285,9 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address, if (user_mode(regs)) store_update_sp = store_updates_sp(regs); + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + /* When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in the * kernel and should generate an OOPS. Unfortunately, in the case of an @@ -415,6 +415,7 @@ good_area: } else if (is_write) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; /* a read */ } else { /* protection fault */ diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 7de4469915f0..fc6679210d83 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -302,6 +302,8 @@ static inline int do_exception(struct pt_regs *regs, int access) address = trans_exc_code & __FAIL_ADDR_MASK; perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400) flags |= FAULT_FLAG_WRITE; down_read(&mm->mmap_sem); diff --git a/arch/score/mm/fault.c b/arch/score/mm/fault.c index 4b71a626d41e..52238983527d 100644 --- a/arch/score/mm/fault.c +++ b/arch/score/mm/fault.c @@ -47,6 +47,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, struct task_struct *tsk = current; struct mm_struct *mm = tsk->mm; const int field = sizeof(unsigned long) * 2; + unsigned long flags = 0; siginfo_t info; int fault; @@ -75,6 +76,9 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, if (in_atomic() || !mm) goto bad_area_nosemaphore; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + down_read(&mm->mmap_sem); vma = find_vma(mm, address); if (!vma) @@ -95,6 +99,7 @@ good_area: if (write) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } else { if (!(vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC))) goto bad_area; @@ -105,7 +110,7 @@ good_area: * make sure we exit gracefully rather than endlessly redo * the fault. */ - fault = handle_mm_fault(mm, vma, address, write); + fault = handle_mm_fault(mm, vma, address, flags); if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) goto out_of_memory; diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c index 1f49c28affa9..541dc6101508 100644 --- a/arch/sh/mm/fault.c +++ b/arch/sh/mm/fault.c @@ -400,9 +400,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, struct mm_struct *mm; struct vm_area_struct * vma; int fault; - int write = error_code & FAULT_CODE_WRITE; - unsigned int flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0)); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; tsk = current; mm = tsk->mm; @@ -476,6 +474,11 @@ good_area: set_thread_fault_code(error_code); + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + if (error_code & FAULT_CODE_WRITE) + flags |= FAULT_FLAG_WRITE; + /* * If for any reason at all we couldn't handle the fault, * make sure we exit gracefully rather than endlessly redo diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c index e98bfda205a2..59dbd4645725 100644 --- a/arch/sparc/mm/fault_32.c +++ b/arch/sparc/mm/fault_32.c @@ -177,8 +177,7 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write, unsigned long g2; int from_user = !(regs->psr & PSR_PS); int fault, code; - unsigned int flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0)); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; if (text_fault) address = regs->pc; @@ -235,6 +234,11 @@ good_area: goto bad_area; } + if (from_user) + flags |= FAULT_FLAG_USER; + if (write) + flags |= FAULT_FLAG_WRITE; + /* * If for any reason at all we couldn't handle the fault, * make sure we exit gracefully rather than endlessly redo @@ -383,6 +387,7 @@ static void force_user_fault(unsigned long address, int write) struct vm_area_struct *vma; struct task_struct *tsk = current; struct mm_struct *mm = tsk->mm; + unsigned int flags = FAULT_FLAG_USER; int code; code = SEGV_MAPERR; @@ -402,11 +407,12 @@ good_area: if (write) { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } else { if (!(vma->vm_flags & (VM_READ | VM_EXEC))) goto bad_area; } - switch (handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0)) { + switch (handle_mm_fault(mm, vma, address, flags)) { case VM_FAULT_SIGBUS: case VM_FAULT_OOM: goto do_sigbus; diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c index 5062ff389e83..2ebec263d685 100644 --- a/arch/sparc/mm/fault_64.c +++ b/arch/sparc/mm/fault_64.c @@ -315,7 +315,8 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs) bad_kernel_pc(regs, address); return; } - } + } else + flags |= FAULT_FLAG_USER; /* * If we're in an interrupt or have no user @@ -418,13 +419,14 @@ good_area: vma->vm_file != NULL) set_thread_fault_code(fault_code | FAULT_CODE_BLKCOMMIT); + + flags |= FAULT_FLAG_WRITE; } else { /* Allow reads even for write-only mappings */ if (!(vma->vm_flags & (VM_READ | VM_EXEC))) goto bad_area; } - flags |= ((fault_code & FAULT_CODE_WRITE) ? FAULT_FLAG_WRITE : 0); fault = handle_mm_fault(mm, vma, address, flags); if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c index 4fd2c0f2a66d..4c288f199453 100644 --- a/arch/tile/mm/fault.c +++ b/arch/tile/mm/fault.c @@ -280,8 +280,7 @@ static int handle_page_fault(struct pt_regs *regs, if (!is_page_fault) write = 1; - flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0)); + flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; is_kernel_mode = !user_mode(regs); @@ -365,6 +364,9 @@ static int handle_page_fault(struct pt_regs *regs, goto bad_area_nosemaphore; } + if (!is_kernel_mode) + flags |= FAULT_FLAG_USER; + /* * When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in the @@ -425,6 +427,7 @@ good_area: #endif if (!(vma->vm_flags & VM_WRITE)) goto bad_area; + flags |= FAULT_FLAG_WRITE; } else { if (!is_page_fault || !(vma->vm_flags & VM_READ)) goto bad_area; diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c index b2f5adf838dd..5c3aef74237f 100644 --- a/arch/um/kernel/trap.c +++ b/arch/um/kernel/trap.c @@ -30,8 +30,7 @@ int handle_page_fault(unsigned long address, unsigned long ip, pmd_t *pmd; pte_t *pte; int err = -EFAULT; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (is_write ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; *code_out = SEGV_MAPERR; @@ -42,6 +41,8 @@ int handle_page_fault(unsigned long address, unsigned long ip, if (in_atomic()) goto out_nosemaphore; + if (is_user) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); @@ -58,12 +59,15 @@ retry: good_area: *code_out = SEGV_ACCERR; - if (is_write && !(vma->vm_flags & VM_WRITE)) - goto out; - - /* Don't require VM_READ|VM_EXEC for write faults! */ - if (!is_write && !(vma->vm_flags & (VM_READ | VM_EXEC))) - goto out; + if (is_write) { + if (!(vma->vm_flags & VM_WRITE)) + goto out; + flags |= FAULT_FLAG_WRITE; + } else { + /* Don't require VM_READ|VM_EXEC for write faults! */ + if (!(vma->vm_flags & (VM_READ | VM_EXEC))) + goto out; + } do { int fault; diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c index 8ed3c4509d84..0dc922dba915 100644 --- a/arch/unicore32/mm/fault.c +++ b/arch/unicore32/mm/fault.c @@ -209,8 +209,7 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs) struct task_struct *tsk; struct mm_struct *mm; int fault, sig, code; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - ((!(fsr ^ 0x12)) ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; tsk = current; mm = tsk->mm; @@ -222,6 +221,11 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (in_atomic() || !mm) goto no_context; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + if (!(fsr ^ 0x12)) + flags |= FAULT_FLAG_WRITE; + /* * As per x86, we may deadlock here. However, since the kernel only * validly references user space from well defined areas of the code, diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 654be4ae3047..6d77c3866faa 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1011,9 +1011,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) unsigned long address; struct mm_struct *mm; int fault; - int write = error_code & PF_WRITE; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; tsk = current; mm = tsk->mm; @@ -1083,6 +1081,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) if (user_mode_vm(regs)) { local_irq_enable(); error_code |= PF_USER; + flags |= FAULT_FLAG_USER; } else { if (regs->flags & X86_EFLAGS_IF) local_irq_enable(); @@ -1109,6 +1108,9 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) return; } + if (error_code & PF_WRITE) + flags |= FAULT_FLAG_WRITE; + /* * When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in diff --git a/arch/xtensa/mm/fault.c b/arch/xtensa/mm/fault.c index 4b7bc8db170f..70fa7bc42b4a 100644 --- a/arch/xtensa/mm/fault.c +++ b/arch/xtensa/mm/fault.c @@ -72,6 +72,8 @@ void do_page_fault(struct pt_regs *regs) address, exccause, regs->pc, is_write? "w":"", is_exec? "x":""); #endif + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; retry: down_read(&mm->mmap_sem); vma = find_vma(mm, address); diff --git a/include/linux/mm.h b/include/linux/mm.h index caf543c7eaa7..3d9b503bcd00 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -176,6 +176,7 @@ extern pgprot_t protection_map[16]; #define FAULT_FLAG_RETRY_NOWAIT 0x10 /* Don't drop mmap_sem and wait when retrying */ #define FAULT_FLAG_KILLABLE 0x20 /* The fault task is in SIGKILL killable region */ #define FAULT_FLAG_TRIED 0x40 /* second try */ +#define FAULT_FLAG_USER 0x80 /* The fault originated in userspace */ /* * vm_fault is filled by the the pagefault handler and passed to the vma's -- cgit v1.2.3 From 3a13c4d761b4b979ba8767f42345fed3274991b0 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 12 Sep 2013 15:13:40 -0700 Subject: x86: finish user fault error path with fatal signal The x86 fault handler bails in the middle of error handling when the task has a fatal signal pending. For a subsequent patch this is a problem in OOM situations because it relies on pagefault_out_of_memory() being called even when the task has been killed, to perform proper per-task OOM state unwinding. Shortcutting the fault like this is a rather minor optimization that saves a few instructions in rare cases. Just remove it for user-triggered faults. Use the opportunity to split the fault retry handling from actual fault errors and add locking documentation that reads suprisingly similar to ARM's. Signed-off-by: Johannes Weiner Reviewed-by: Michal Hocko Acked-by: KOSAKI Motohiro Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: azurIt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/mm/fault.c | 35 +++++++++++++++++------------------ 1 file changed, 17 insertions(+), 18 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 6d77c3866faa..3aaeffcfd67a 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -842,23 +842,15 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address, force_sig_info_fault(SIGBUS, code, address, tsk, fault); } -static noinline int +static noinline void mm_fault_error(struct pt_regs *regs, unsigned long error_code, unsigned long address, unsigned int fault) { - /* - * Pagefault was interrupted by SIGKILL. We have no reason to - * continue pagefault. - */ - if (fatal_signal_pending(current)) { - if (!(fault & VM_FAULT_RETRY)) - up_read(¤t->mm->mmap_sem); - if (!(error_code & PF_USER)) - no_context(regs, error_code, address, 0, 0); - return 1; + if (fatal_signal_pending(current) && !(error_code & PF_USER)) { + up_read(¤t->mm->mmap_sem); + no_context(regs, error_code, address, 0, 0); + return; } - if (!(fault & VM_FAULT_ERROR)) - return 0; if (fault & VM_FAULT_OOM) { /* Kernel mode? Handle exceptions or die: */ @@ -866,7 +858,7 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code, up_read(¤t->mm->mmap_sem); no_context(regs, error_code, address, SIGSEGV, SEGV_MAPERR); - return 1; + return; } up_read(¤t->mm->mmap_sem); @@ -884,7 +876,6 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code, else BUG(); } - return 1; } static int spurious_fault_check(unsigned long error_code, pte_t *pte) @@ -1189,9 +1180,17 @@ good_area: */ fault = handle_mm_fault(mm, vma, address, flags); - if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) { - if (mm_fault_error(regs, error_code, address, fault)) - return; + /* + * If we need to retry but a fatal signal is pending, handle the + * signal first. We do not need to release the mmap_sem because it + * would already be released in __lock_page_or_retry in mm/filemap.c. + */ + if (unlikely((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))) + return; + + if (unlikely(fault & VM_FAULT_ERROR)) { + mm_fault_error(regs, error_code, address, fault); + return; } /* -- cgit v1.2.3 From 519e52473ebe9db5cdef44670d5a97f1fd53d721 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 12 Sep 2013 15:13:42 -0700 Subject: mm: memcg: enable memcg OOM killer only for user faults System calls and kernel faults (uaccess, gup) can handle an out of memory situation gracefully and just return -ENOMEM. Enable the memcg OOM killer only for user faults, where it's really the only option available. Signed-off-by: Johannes Weiner Acked-by: Michal Hocko Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: azurIt Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/sched.h | 3 +++ mm/filemap.c | 11 ++++++++++- mm/memcontrol.c | 2 +- mm/memory.c | 40 ++++++++++++++++++++++++++++++---------- 5 files changed, 88 insertions(+), 12 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index d4d1f9b0dbba..34ac6497d01a 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -151,6 +151,37 @@ extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, extern void mem_cgroup_replace_page_cache(struct page *oldpage, struct page *newpage); +/** + * mem_cgroup_toggle_oom - toggle the memcg OOM killer for the current task + * @new: true to enable, false to disable + * + * Toggle whether a failed memcg charge should invoke the OOM killer + * or just return -ENOMEM. Returns the previous toggle state. + */ +static inline bool mem_cgroup_toggle_oom(bool new) +{ + bool old; + + old = current->memcg_oom.may_oom; + current->memcg_oom.may_oom = new; + + return old; +} + +static inline void mem_cgroup_enable_oom(void) +{ + bool old = mem_cgroup_toggle_oom(true); + + WARN_ON(old == true); +} + +static inline void mem_cgroup_disable_oom(void) +{ + bool old = mem_cgroup_toggle_oom(false); + + WARN_ON(old == false); +} + #ifdef CONFIG_MEMCG_SWAP extern int do_swap_account; #endif @@ -383,6 +414,19 @@ static inline void mem_cgroup_end_update_page_stat(struct page *page, { } +static inline bool mem_cgroup_toggle_oom(bool new) +{ + return false; +} + +static inline void mem_cgroup_enable_oom(void) +{ +} + +static inline void mem_cgroup_disable_oom(void) +{ +} + static inline void mem_cgroup_inc_page_stat(struct page *page, enum mem_cgroup_page_stat_item idx) { diff --git a/include/linux/sched.h b/include/linux/sched.h index 45f254dddafc..9ce1fa53031f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1393,6 +1393,9 @@ struct task_struct { unsigned long memsw_nr_pages; /* uncharged mem+swap usage */ } memcg_batch; unsigned int memcg_kmem_skip_account; + struct memcg_oom_info { + unsigned int may_oom:1; + } memcg_oom; #endif #ifdef CONFIG_UPROBES struct uprobe_task *utask; diff --git a/mm/filemap.c b/mm/filemap.c index e607728db4a8..e3b6fc8c0b7b 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1614,6 +1614,7 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) struct inode *inode = mapping->host; pgoff_t offset = vmf->pgoff; struct page *page; + bool memcg_oom; pgoff_t size; int ret = 0; @@ -1622,7 +1623,11 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) return VM_FAULT_SIGBUS; /* - * Do we have something in the page cache already? + * Do we have something in the page cache already? Either + * way, try readahead, but disable the memcg OOM killer for it + * as readahead is optional and no errors are propagated up + * the fault stack. The OOM killer is enabled while trying to + * instantiate the faulting page individually below. */ page = find_get_page(mapping, offset); if (likely(page) && !(vmf->flags & FAULT_FLAG_TRIED)) { @@ -1630,10 +1635,14 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) * We found the page, so try async readahead before * waiting for the lock. */ + memcg_oom = mem_cgroup_toggle_oom(false); do_async_mmap_readahead(vma, ra, file, page, offset); + mem_cgroup_toggle_oom(memcg_oom); } else if (!page) { /* No page in the page cache at all */ + memcg_oom = mem_cgroup_toggle_oom(false); do_sync_mmap_readahead(vma, ra, file, offset); + mem_cgroup_toggle_oom(memcg_oom); count_vm_event(PGMAJFAULT); mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); ret = VM_FAULT_MAJOR; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c4524458b7d0..0980bbf6438d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2454,7 +2454,7 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, return CHARGE_RETRY; /* If we don't need to call oom-killer at el, return immediately */ - if (!oom_check) + if (!oom_check || !current->memcg_oom.may_oom) return CHARGE_NOMEM; /* check OOM */ if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask, get_order(csize))) diff --git a/mm/memory.c b/mm/memory.c index 2b73dbde2274..a8f9deab8719 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3754,22 +3754,14 @@ unlock: /* * By the time we get here, we already hold the mm semaphore */ -int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long address, unsigned int flags) +static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long address, unsigned int flags) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte; - __set_current_state(TASK_RUNNING); - - count_vm_event(PGFAULT); - mem_cgroup_count_vm_event(mm, PGFAULT); - - /* do counter updates before entering really critical section. */ - check_sync_rss_stat(current); - if (unlikely(is_vm_hugetlb_page(vma))) return hugetlb_fault(mm, vma, address, flags); @@ -3850,6 +3842,34 @@ retry: return handle_pte_fault(mm, vma, address, pte, pmd, flags); } +int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long address, unsigned int flags) +{ + int ret; + + __set_current_state(TASK_RUNNING); + + count_vm_event(PGFAULT); + mem_cgroup_count_vm_event(mm, PGFAULT); + + /* do counter updates before entering really critical section. */ + check_sync_rss_stat(current); + + /* + * Enable the memcg OOM handling for faults triggered in user + * space. Kernel faults are handled more gracefully. + */ + if (flags & FAULT_FLAG_USER) + mem_cgroup_enable_oom(); + + ret = __handle_mm_fault(mm, vma, address, flags); + + if (flags & FAULT_FLAG_USER) + mem_cgroup_disable_oom(); + + return ret; +} + #ifndef __PAGETABLE_PUD_FOLDED /* * Allocate page upper directory. -- cgit v1.2.3 From fb2a6fc56be66c169f8b80e07ed999ba453a2db2 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 12 Sep 2013 15:13:43 -0700 Subject: mm: memcg: rework and document OOM waiting and wakeup The memcg OOM handler open-codes a sleeping lock for OOM serialization (trylock, wait, repeat) because the required locking is so specific to memcg hierarchies. However, it would be nice if this construct would be clearly recognizable and not be as obfuscated as it is right now. Clean up as follows: 1. Remove the return value of mem_cgroup_oom_unlock() 2. Rename mem_cgroup_oom_lock() to mem_cgroup_oom_trylock(). 3. Pull the prepare_to_wait() out of the memcg_oom_lock scope. This makes it more obvious that the task has to be on the waitqueue before attempting to OOM-trylock the hierarchy, to not miss any wakeups before going to sleep. It just didn't matter until now because it was all lumped together into the global memcg_oom_lock spinlock section. 4. Pull the mem_cgroup_oom_notify() out of the memcg_oom_lock scope. It is proctected by the hierarchical OOM-lock. 5. The memcg_oom_lock spinlock is only required to propagate the OOM lock in any given hierarchy atomically. Restrict its scope to mem_cgroup_oom_(trylock|unlock). 6. Do not wake up the waitqueue unconditionally at the end of the function. Only the lockholder has to wake up the next in line after releasing the lock. Note that the lockholder kicks off the OOM-killer, which in turn leads to wakeups from the uncharges of the exiting task. But a contender is not guaranteed to see them if it enters the OOM path after the OOM kills but before the lockholder releases the lock. Thus there has to be an explicit wakeup after releasing the lock. 7. Put the OOM task on the waitqueue before marking the hierarchy as under OOM as that is the point where we start to receive wakeups. No point in listening before being on the waitqueue. 8. Likewise, unmark the hierarchy before finishing the sleep, for symmetry. Signed-off-by: Johannes Weiner Acked-by: Michal Hocko Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: azurIt Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 83 ++++++++++++++++++++++++++++++++------------------------- 1 file changed, 46 insertions(+), 37 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0980bbf6438d..04250cbf46c6 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1916,15 +1916,18 @@ mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, return SKIP; } +static DEFINE_SPINLOCK(memcg_oom_lock); + /* * Check OOM-Killer is already running under our hierarchy. * If someone is running, return false. - * Has to be called with memcg_oom_lock */ -static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg) +static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) { struct mem_cgroup *iter, *failed = NULL; + spin_lock(&memcg_oom_lock); + for_each_mem_cgroup_tree(iter, memcg) { if (iter->oom_lock) { /* @@ -1938,33 +1941,33 @@ static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg) iter->oom_lock = true; } - if (!failed) - return true; - - /* - * OK, we failed to lock the whole subtree so we have to clean up - * what we set up to the failing subtree - */ - for_each_mem_cgroup_tree(iter, memcg) { - if (iter == failed) { - mem_cgroup_iter_break(memcg, iter); - break; + if (failed) { + /* + * OK, we failed to lock the whole subtree so we have + * to clean up what we set up to the failing subtree + */ + for_each_mem_cgroup_tree(iter, memcg) { + if (iter == failed) { + mem_cgroup_iter_break(memcg, iter); + break; + } + iter->oom_lock = false; } - iter->oom_lock = false; } - return false; + + spin_unlock(&memcg_oom_lock); + + return !failed; } -/* - * Has to be called with memcg_oom_lock - */ -static int mem_cgroup_oom_unlock(struct mem_cgroup *memcg) +static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) { struct mem_cgroup *iter; + spin_lock(&memcg_oom_lock); for_each_mem_cgroup_tree(iter, memcg) iter->oom_lock = false; - return 0; + spin_unlock(&memcg_oom_lock); } static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) @@ -1988,7 +1991,6 @@ static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) atomic_add_unless(&iter->under_oom, -1, 0); } -static DEFINE_SPINLOCK(memcg_oom_lock); static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); struct oom_wait_info { @@ -2035,45 +2037,52 @@ static bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, int order) { struct oom_wait_info owait; - bool locked, need_to_kill; + bool locked; owait.memcg = memcg; owait.wait.flags = 0; owait.wait.func = memcg_oom_wake_function; owait.wait.private = current; INIT_LIST_HEAD(&owait.wait.task_list); - need_to_kill = true; - mem_cgroup_mark_under_oom(memcg); - /* At first, try to OOM lock hierarchy under memcg.*/ - spin_lock(&memcg_oom_lock); - locked = mem_cgroup_oom_lock(memcg); /* + * As with any blocking lock, a contender needs to start + * listening for wakeups before attempting the trylock, + * otherwise it can miss the wakeup from the unlock and sleep + * indefinitely. This is just open-coded because our locking + * is so particular to memcg hierarchies. + * * Even if signal_pending(), we can't quit charge() loop without * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL * under OOM is always welcomed, use TASK_KILLABLE here. */ prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); - if (!locked || memcg->oom_kill_disable) - need_to_kill = false; + mem_cgroup_mark_under_oom(memcg); + + locked = mem_cgroup_oom_trylock(memcg); + if (locked) mem_cgroup_oom_notify(memcg); - spin_unlock(&memcg_oom_lock); - if (need_to_kill) { + if (locked && !memcg->oom_kill_disable) { + mem_cgroup_unmark_under_oom(memcg); finish_wait(&memcg_oom_waitq, &owait.wait); mem_cgroup_out_of_memory(memcg, mask, order); } else { schedule(); + mem_cgroup_unmark_under_oom(memcg); finish_wait(&memcg_oom_waitq, &owait.wait); } - spin_lock(&memcg_oom_lock); - if (locked) - mem_cgroup_oom_unlock(memcg); - memcg_wakeup_oom(memcg); - spin_unlock(&memcg_oom_lock); - mem_cgroup_unmark_under_oom(memcg); + if (locked) { + mem_cgroup_oom_unlock(memcg); + /* + * There is no guarantee that an OOM-lock contender + * sees the wakeups triggered by the OOM kill + * uncharges. Wake any sleepers explicitely. + */ + memcg_oom_recover(memcg); + } if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) return false; -- cgit v1.2.3 From 3812c8c8f3953921ef18544110dafc3505c1ac62 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 12 Sep 2013 15:13:44 -0700 Subject: mm: memcg: do not trap chargers with full callstack on OOM The memcg OOM handling is incredibly fragile and can deadlock. When a task fails to charge memory, it invokes the OOM killer and loops right there in the charge code until it succeeds. Comparably, any other task that enters the charge path at this point will go to a waitqueue right then and there and sleep until the OOM situation is resolved. The problem is that these tasks may hold filesystem locks and the mmap_sem; locks that the selected OOM victim may need to exit. For example, in one reported case, the task invoking the OOM killer was about to charge a page cache page during a write(), which holds the i_mutex. The OOM killer selected a task that was just entering truncate() and trying to acquire the i_mutex: OOM invoking task: mem_cgroup_handle_oom+0x241/0x3b0 mem_cgroup_cache_charge+0xbe/0xe0 add_to_page_cache_locked+0x4c/0x140 add_to_page_cache_lru+0x22/0x50 grab_cache_page_write_begin+0x8b/0xe0 ext3_write_begin+0x88/0x270 generic_file_buffered_write+0x116/0x290 __generic_file_aio_write+0x27c/0x480 generic_file_aio_write+0x76/0xf0 # takes ->i_mutex do_sync_write+0xea/0x130 vfs_write+0xf3/0x1f0 sys_write+0x51/0x90 system_call_fastpath+0x18/0x1d OOM kill victim: do_truncate+0x58/0xa0 # takes i_mutex do_last+0x250/0xa30 path_openat+0xd7/0x440 do_filp_open+0x49/0xa0 do_sys_open+0x106/0x240 sys_open+0x20/0x30 system_call_fastpath+0x18/0x1d The OOM handling task will retry the charge indefinitely while the OOM killed task is not releasing any resources. A similar scenario can happen when the kernel OOM killer for a memcg is disabled and a userspace task is in charge of resolving OOM situations. In this case, ALL tasks that enter the OOM path will be made to sleep on the OOM waitqueue and wait for userspace to free resources or increase the group's limit. But a userspace OOM handler is prone to deadlock itself on the locks held by the waiting tasks. For example one of the sleeping tasks may be stuck in a brk() call with the mmap_sem held for writing but the userspace handler, in order to pick an optimal victim, may need to read files from /proc/, which tries to acquire the same mmap_sem for reading and deadlocks. This patch changes the way tasks behave after detecting a memcg OOM and makes sure nobody loops or sleeps with locks held: 1. When OOMing in a user fault, invoke the OOM killer and restart the fault instead of looping on the charge attempt. This way, the OOM victim can not get stuck on locks the looping task may hold. 2. When OOMing in a user fault but somebody else is handling it (either the kernel OOM killer or a userspace handler), don't go to sleep in the charge context. Instead, remember the OOMing memcg in the task struct and then fully unwind the page fault stack with -ENOMEM. pagefault_out_of_memory() will then call back into the memcg code to check if the -ENOMEM came from the memcg, and then either put the task to sleep on the memcg's OOM waitqueue or just restart the fault. The OOM victim can no longer get stuck on any lock a sleeping task may hold. Debugged by Michal Hocko. Signed-off-by: Johannes Weiner Reported-by: azurIt Acked-by: Michal Hocko Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 21 +++++++ include/linux/sched.h | 4 ++ mm/memcontrol.c | 154 +++++++++++++++++++++++++++++++-------------- mm/memory.c | 3 + mm/oom_kill.c | 7 ++- 5 files changed, 140 insertions(+), 49 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 34ac6497d01a..89d576cfcc4c 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -157,6 +157,10 @@ extern void mem_cgroup_replace_page_cache(struct page *oldpage, * * Toggle whether a failed memcg charge should invoke the OOM killer * or just return -ENOMEM. Returns the previous toggle state. + * + * NOTE: Any path that enables the OOM killer before charging must + * call mem_cgroup_oom_synchronize() afterward to finalize the + * OOM handling and clean up. */ static inline bool mem_cgroup_toggle_oom(bool new) { @@ -182,6 +186,13 @@ static inline void mem_cgroup_disable_oom(void) WARN_ON(old == false); } +static inline bool task_in_memcg_oom(struct task_struct *p) +{ + return p->memcg_oom.in_memcg_oom; +} + +bool mem_cgroup_oom_synchronize(void); + #ifdef CONFIG_MEMCG_SWAP extern int do_swap_account; #endif @@ -427,6 +438,16 @@ static inline void mem_cgroup_disable_oom(void) { } +static inline bool task_in_memcg_oom(struct task_struct *p) +{ + return false; +} + +static inline bool mem_cgroup_oom_synchronize(void) +{ + return false; +} + static inline void mem_cgroup_inc_page_stat(struct page *page, enum mem_cgroup_page_stat_item idx) { diff --git a/include/linux/sched.h b/include/linux/sched.h index 9ce1fa53031f..6682da36b293 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1395,6 +1395,10 @@ struct task_struct { unsigned int memcg_kmem_skip_account; struct memcg_oom_info { unsigned int may_oom:1; + unsigned int in_memcg_oom:1; + unsigned int oom_locked:1; + int wakeups; + struct mem_cgroup *wait_on_memcg; } memcg_oom; #endif #ifdef CONFIG_UPROBES diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 04250cbf46c6..4b5cfb509270 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -255,6 +255,7 @@ struct mem_cgroup { bool oom_lock; atomic_t under_oom; + atomic_t oom_wakeups; int swappiness; /* OOM-Killer disable */ @@ -2020,6 +2021,7 @@ static int memcg_oom_wake_function(wait_queue_t *wait, static void memcg_wakeup_oom(struct mem_cgroup *memcg) { + atomic_inc(&memcg->oom_wakeups); /* for filtering, pass "memcg" as argument. */ __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); } @@ -2031,19 +2033,17 @@ static void memcg_oom_recover(struct mem_cgroup *memcg) } /* - * try to call OOM killer. returns false if we should exit memory-reclaim loop. + * try to call OOM killer */ -static bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, - int order) +static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) { - struct oom_wait_info owait; bool locked; + int wakeups; - owait.memcg = memcg; - owait.wait.flags = 0; - owait.wait.func = memcg_oom_wake_function; - owait.wait.private = current; - INIT_LIST_HEAD(&owait.wait.task_list); + if (!current->memcg_oom.may_oom) + return; + + current->memcg_oom.in_memcg_oom = 1; /* * As with any blocking lock, a contender needs to start @@ -2051,12 +2051,8 @@ static bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, * otherwise it can miss the wakeup from the unlock and sleep * indefinitely. This is just open-coded because our locking * is so particular to memcg hierarchies. - * - * Even if signal_pending(), we can't quit charge() loop without - * accounting. So, UNINTERRUPTIBLE is appropriate. But SIGKILL - * under OOM is always welcomed, use TASK_KILLABLE here. */ - prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); + wakeups = atomic_read(&memcg->oom_wakeups); mem_cgroup_mark_under_oom(memcg); locked = mem_cgroup_oom_trylock(memcg); @@ -2066,15 +2062,95 @@ static bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, if (locked && !memcg->oom_kill_disable) { mem_cgroup_unmark_under_oom(memcg); - finish_wait(&memcg_oom_waitq, &owait.wait); mem_cgroup_out_of_memory(memcg, mask, order); + mem_cgroup_oom_unlock(memcg); + /* + * There is no guarantee that an OOM-lock contender + * sees the wakeups triggered by the OOM kill + * uncharges. Wake any sleepers explicitely. + */ + memcg_oom_recover(memcg); } else { - schedule(); - mem_cgroup_unmark_under_oom(memcg); - finish_wait(&memcg_oom_waitq, &owait.wait); + /* + * A system call can just return -ENOMEM, but if this + * is a page fault and somebody else is handling the + * OOM already, we need to sleep on the OOM waitqueue + * for this memcg until the situation is resolved. + * Which can take some time because it might be + * handled by a userspace task. + * + * However, this is the charge context, which means + * that we may sit on a large call stack and hold + * various filesystem locks, the mmap_sem etc. and we + * don't want the OOM handler to deadlock on them + * while we sit here and wait. Store the current OOM + * context in the task_struct, then return -ENOMEM. + * At the end of the page fault handler, with the + * stack unwound, pagefault_out_of_memory() will check + * back with us by calling + * mem_cgroup_oom_synchronize(), possibly putting the + * task to sleep. + */ + current->memcg_oom.oom_locked = locked; + current->memcg_oom.wakeups = wakeups; + css_get(&memcg->css); + current->memcg_oom.wait_on_memcg = memcg; } +} + +/** + * mem_cgroup_oom_synchronize - complete memcg OOM handling + * + * This has to be called at the end of a page fault if the the memcg + * OOM handler was enabled and the fault is returning %VM_FAULT_OOM. + * + * Memcg supports userspace OOM handling, so failed allocations must + * sleep on a waitqueue until the userspace task resolves the + * situation. Sleeping directly in the charge context with all kinds + * of locks held is not a good idea, instead we remember an OOM state + * in the task and mem_cgroup_oom_synchronize() has to be called at + * the end of the page fault to put the task to sleep and clean up the + * OOM state. + * + * Returns %true if an ongoing memcg OOM situation was detected and + * finalized, %false otherwise. + */ +bool mem_cgroup_oom_synchronize(void) +{ + struct oom_wait_info owait; + struct mem_cgroup *memcg; + + /* OOM is global, do not handle */ + if (!current->memcg_oom.in_memcg_oom) + return false; + + /* + * We invoked the OOM killer but there is a chance that a kill + * did not free up any charges. Everybody else might already + * be sleeping, so restart the fault and keep the rampage + * going until some charges are released. + */ + memcg = current->memcg_oom.wait_on_memcg; + if (!memcg) + goto out; + + if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) + goto out_memcg; + + owait.memcg = memcg; + owait.wait.flags = 0; + owait.wait.func = memcg_oom_wake_function; + owait.wait.private = current; + INIT_LIST_HEAD(&owait.wait.task_list); - if (locked) { + prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); + /* Only sleep if we didn't miss any wakeups since OOM */ + if (atomic_read(&memcg->oom_wakeups) == current->memcg_oom.wakeups) + schedule(); + finish_wait(&memcg_oom_waitq, &owait.wait); +out_memcg: + mem_cgroup_unmark_under_oom(memcg); + if (current->memcg_oom.oom_locked) { mem_cgroup_oom_unlock(memcg); /* * There is no guarantee that an OOM-lock contender @@ -2083,11 +2159,10 @@ static bool mem_cgroup_handle_oom(struct mem_cgroup *memcg, gfp_t mask, */ memcg_oom_recover(memcg); } - - if (test_thread_flag(TIF_MEMDIE) || fatal_signal_pending(current)) - return false; - /* Give chance to dying process */ - schedule_timeout_uninterruptible(1); + css_put(&memcg->css); + current->memcg_oom.wait_on_memcg = NULL; +out: + current->memcg_oom.in_memcg_oom = 0; return true; } @@ -2400,12 +2475,11 @@ enum { CHARGE_RETRY, /* need to retry but retry is not bad */ CHARGE_NOMEM, /* we can't do more. return -ENOMEM */ CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */ - CHARGE_OOM_DIE, /* the current is killed because of OOM */ }; static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, unsigned int nr_pages, unsigned int min_pages, - bool oom_check) + bool invoke_oom) { unsigned long csize = nr_pages * PAGE_SIZE; struct mem_cgroup *mem_over_limit; @@ -2462,14 +2536,10 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, if (mem_cgroup_wait_acct_move(mem_over_limit)) return CHARGE_RETRY; - /* If we don't need to call oom-killer at el, return immediately */ - if (!oom_check || !current->memcg_oom.may_oom) - return CHARGE_NOMEM; - /* check OOM */ - if (!mem_cgroup_handle_oom(mem_over_limit, gfp_mask, get_order(csize))) - return CHARGE_OOM_DIE; + if (invoke_oom) + mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(csize)); - return CHARGE_RETRY; + return CHARGE_NOMEM; } /* @@ -2572,7 +2642,7 @@ again: } do { - bool oom_check; + bool invoke_oom = oom && !nr_oom_retries; /* If killed, bypass charge */ if (fatal_signal_pending(current)) { @@ -2580,14 +2650,8 @@ again: goto bypass; } - oom_check = false; - if (oom && !nr_oom_retries) { - oom_check = true; - nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES; - } - - ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, nr_pages, - oom_check); + ret = mem_cgroup_do_charge(memcg, gfp_mask, batch, + nr_pages, invoke_oom); switch (ret) { case CHARGE_OK: break; @@ -2600,16 +2664,12 @@ again: css_put(&memcg->css); goto nomem; case CHARGE_NOMEM: /* OOM routine works */ - if (!oom) { + if (!oom || invoke_oom) { css_put(&memcg->css); goto nomem; } - /* If oom, we never return -ENOMEM */ nr_oom_retries--; break; - case CHARGE_OOM_DIE: /* Killed by OOM Killer */ - css_put(&memcg->css); - goto bypass; } } while (ret != CHARGE_OK); diff --git a/mm/memory.c b/mm/memory.c index a8f9deab8719..5ec6f199e685 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3867,6 +3867,9 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (flags & FAULT_FLAG_USER) mem_cgroup_disable_oom(); + if (WARN_ON(task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))) + mem_cgroup_oom_synchronize(); + return ret; } diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 98e75f2ac7bc..314e9d274381 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -678,9 +678,12 @@ out: */ void pagefault_out_of_memory(void) { - struct zonelist *zonelist = node_zonelist(first_online_node, - GFP_KERNEL); + struct zonelist *zonelist; + if (mem_cgroup_oom_synchronize()) + return; + + zonelist = node_zonelist(first_online_node, GFP_KERNEL); if (try_set_zonelist_oom(zonelist, GFP_KERNEL)) { out_of_memory(NULL, 0, 0, NULL, false); clear_zonelist_oom(zonelist, GFP_KERNEL); -- cgit v1.2.3 From 34ff8dc08956098563989d8599840b130be81252 Mon Sep 17 00:00:00 2001 From: Sha Zhengju Date: Thu, 12 Sep 2013 15:13:46 -0700 Subject: memcg: correct RESOURCE_MAX to ULLONG_MAX Current RESOURCE_MAX is ULONG_MAX, but the value we used to set resource limit is unsigned long long, so we can set bigger value than that which is strange. The XXX_MAX should be reasonable max value, bigger than that should be overflow. Notice that this change will affect user output of default *.limit_in_bytes: before change: $ cat /cgroup/memory/memory.limit_in_bytes 9223372036854775807 after change: $ cat /cgroup/memory/memory.limit_in_bytes 18446744073709551615 But it doesn't alter the API in term of input - we can still use "echo -1 > *.limit_in_bytes" to reset the numbers to "unlimited". Signed-off-by: Sha Zhengju Signed-off-by: Qiang Huang Acked-by: Michal Hocko Cc: Daisuke Nishimura Cc: Jeff Liu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/res_counter.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h index 96a509b6be04..586bc7cb1dcf 100644 --- a/include/linux/res_counter.h +++ b/include/linux/res_counter.h @@ -54,7 +54,7 @@ struct res_counter { struct res_counter *parent; }; -#define RESOURCE_MAX (unsigned long long)LLONG_MAX +#define RESOURCE_MAX ULLONG_MAX /** * Helpers to interact with userspace -- cgit v1.2.3 From 6de5a8bfcae6e3b427d642eff078d8305b324b52 Mon Sep 17 00:00:00 2001 From: Sha Zhengju Date: Thu, 12 Sep 2013 15:13:47 -0700 Subject: memcg: rename RESOURCE_MAX to RES_COUNTER_MAX RESOURCE_MAX is far too general name, change it to RES_COUNTER_MAX. Signed-off-by: Sha Zhengju Signed-off-by: Qiang Huang Acked-by: Michal Hocko Cc: Daisuke Nishimura Cc: Jeff Liu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/res_counter.h | 2 +- kernel/res_counter.c | 8 ++++---- mm/memcontrol.c | 4 ++-- net/ipv4/tcp_memcontrol.c | 10 +++++----- 4 files changed, 12 insertions(+), 12 deletions(-) diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h index 586bc7cb1dcf..201a69749659 100644 --- a/include/linux/res_counter.h +++ b/include/linux/res_counter.h @@ -54,7 +54,7 @@ struct res_counter { struct res_counter *parent; }; -#define RESOURCE_MAX ULLONG_MAX +#define RES_COUNTER_MAX ULLONG_MAX /** * Helpers to interact with userspace diff --git a/kernel/res_counter.c b/kernel/res_counter.c index ff55247e7049..3f0417f97e76 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -17,8 +17,8 @@ void res_counter_init(struct res_counter *counter, struct res_counter *parent) { spin_lock_init(&counter->lock); - counter->limit = RESOURCE_MAX; - counter->soft_limit = RESOURCE_MAX; + counter->limit = RES_COUNTER_MAX; + counter->soft_limit = RES_COUNTER_MAX; counter->parent = parent; } @@ -182,12 +182,12 @@ int res_counter_memparse_write_strategy(const char *buf, { char *end; - /* return RESOURCE_MAX(unlimited) if "-1" is specified */ + /* return RES_COUNTER_MAX(unlimited) if "-1" is specified */ if (*buf == '-') { *res = simple_strtoull(buf + 1, &end, 10); if (*res != 1 || *end != '\0') return -EINVAL; - *res = RESOURCE_MAX; + *res = RES_COUNTER_MAX; return 0; } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 4b5cfb509270..2c71f243186e 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4967,7 +4967,7 @@ static int memcg_update_kmem_limit(struct cgroup_subsys_state *css, u64 val) */ mutex_lock(&memcg_create_mutex); mutex_lock(&set_limit_mutex); - if (!memcg->kmem_account_flags && val != RESOURCE_MAX) { + if (!memcg->kmem_account_flags && val != RES_COUNTER_MAX) { if (cgroup_task_count(css->cgroup) || memcg_has_children(memcg)) { ret = -EBUSY; goto out; @@ -4977,7 +4977,7 @@ static int memcg_update_kmem_limit(struct cgroup_subsys_state *css, u64 val) ret = memcg_update_cache_sizes(memcg); if (ret) { - res_counter_set_limit(&memcg->kmem, RESOURCE_MAX); + res_counter_set_limit(&memcg->kmem, RES_COUNTER_MAX); goto out; } static_key_slow_inc(&memcg_kmem_enabled_key); diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c index 8a57d79b0b16..559d4ae6ebf4 100644 --- a/net/ipv4/tcp_memcontrol.c +++ b/net/ipv4/tcp_memcontrol.c @@ -87,8 +87,8 @@ static int tcp_update_limit(struct mem_cgroup *memcg, u64 val) if (!cg_proto) return -EINVAL; - if (val > RESOURCE_MAX) - val = RESOURCE_MAX; + if (val > RES_COUNTER_MAX) + val = RES_COUNTER_MAX; tcp = tcp_from_cgproto(cg_proto); @@ -101,9 +101,9 @@ static int tcp_update_limit(struct mem_cgroup *memcg, u64 val) tcp->tcp_prot_mem[i] = min_t(long, val >> PAGE_SHIFT, net->ipv4.sysctl_tcp_mem[i]); - if (val == RESOURCE_MAX) + if (val == RES_COUNTER_MAX) clear_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags); - else if (val != RESOURCE_MAX) { + else if (val != RES_COUNTER_MAX) { /* * The active bit needs to be written after the static_key * update. This is what guarantees that the socket activation @@ -187,7 +187,7 @@ static u64 tcp_cgroup_read(struct cgroup_subsys_state *css, struct cftype *cft) switch (cft->private) { case RES_LIMIT: - val = tcp_read_stat(memcg, RES_LIMIT, RESOURCE_MAX); + val = tcp_read_stat(memcg, RES_LIMIT, RES_COUNTER_MAX); break; case RES_USAGE: val = tcp_read_usage(memcg); -- cgit v1.2.3 From 3af3351676c3deecfd632f47719fb0d13a061ba8 Mon Sep 17 00:00:00 2001 From: Sha Zhengju Date: Thu, 12 Sep 2013 15:13:48 -0700 Subject: memcg: avoid overflow caused by PAGE_ALIGN Since PAGE_ALIGN is aligning up(the next page boundary), so after PAGE_ALIGN, the value might be overflow, such as write the MAX value to *.limit_in_bytes. $ cat /cgroup/memory/memory.limit_in_bytes 18446744073709551615 # echo 18446744073709551615 > /cgroup/memory/memory.limit_in_bytes bash: echo: write error: Invalid argument Some user programs might depend on such behaviours(like libcg, we read the value in snapshot, then use the value to reset cgroup later), and that will cause confusion. So we need to fix it. Signed-off-by: Sha Zhengju Signed-off-by: Qiang Huang Acked-by: Michal Hocko Cc: Daisuke Nishimura Cc: Jeff Liu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/res_counter.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/res_counter.c b/kernel/res_counter.c index 3f0417f97e76..085d3ae478fe 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -195,6 +195,10 @@ int res_counter_memparse_write_strategy(const char *buf, if (*end != '\0') return -EINVAL; - *res = PAGE_ALIGN(*res); + if (PAGE_ALIGN(*res) >= *res) + *res = PAGE_ALIGN(*res); + else + *res = RES_COUNTER_MAX; + return 0; } -- cgit v1.2.3 From 1a36e59d4833de19120dc7482c61ef69e228c73c Mon Sep 17 00:00:00 2001 From: Sha Zhengju Date: Thu, 12 Sep 2013 15:13:49 -0700 Subject: memcg: reduce function dereference This function dereferences res far too often, so optimize it. Signed-off-by: Sha Zhengju Signed-off-by: Qiang Huang Acked-by: Michal Hocko Cc: Daisuke Nishimura Cc: Jeff Liu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/res_counter.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/kernel/res_counter.c b/kernel/res_counter.c index 085d3ae478fe..4aa8a305aede 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -178,27 +178,30 @@ u64 res_counter_read_u64(struct res_counter *counter, int member) #endif int res_counter_memparse_write_strategy(const char *buf, - unsigned long long *res) + unsigned long long *resp) { char *end; + unsigned long long res; /* return RES_COUNTER_MAX(unlimited) if "-1" is specified */ if (*buf == '-') { - *res = simple_strtoull(buf + 1, &end, 10); - if (*res != 1 || *end != '\0') + res = simple_strtoull(buf + 1, &end, 10); + if (res != 1 || *end != '\0') return -EINVAL; - *res = RES_COUNTER_MAX; + *resp = RES_COUNTER_MAX; return 0; } - *res = memparse(buf, &end); + res = memparse(buf, &end); if (*end != '\0') return -EINVAL; - if (PAGE_ALIGN(*res) >= *res) - *res = PAGE_ALIGN(*res); + if (PAGE_ALIGN(res) >= res) + res = PAGE_ALIGN(res); else - *res = RES_COUNTER_MAX; + res = RES_COUNTER_MAX; + + *resp = res; return 0; } -- cgit v1.2.3 From 68b4876d996e8749142b2895bc2e251448996363 Mon Sep 17 00:00:00 2001 From: Sha Zhengju Date: Thu, 12 Sep 2013 15:13:50 -0700 Subject: memcg: remove MEMCG_NR_FILE_MAPPED While accounting memcg page stat, it's not worth to use MEMCG_NR_FILE_MAPPED as an extra layer of indirection because of the complexity and presumed performance overhead. We can use MEM_CGROUP_STAT_FILE_MAPPED directly. Signed-off-by: Sha Zhengju Acked-by: KAMEZAWA Hiroyuki Acked-by: Michal Hocko Acked-by: Fengguang Wu Reviewed-by: Greg Thelen Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 27 +++++++++++++++++++-------- mm/memcontrol.c | 25 +------------------------ mm/rmap.c | 4 ++-- 3 files changed, 22 insertions(+), 34 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 89d576cfcc4c..f952a07ce7a9 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -30,9 +30,20 @@ struct page; struct mm_struct; struct kmem_cache; -/* Stats that can be updated by kernel. */ -enum mem_cgroup_page_stat_item { - MEMCG_NR_FILE_MAPPED, /* # of pages charged as file rss */ +/* + * The corresponding mem_cgroup_stat_names is defined in mm/memcontrol.c, + * These two lists should keep in accord with each other. + */ +enum mem_cgroup_stat_index { + /* + * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. + */ + MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ + MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ + MEM_CGROUP_STAT_RSS_HUGE, /* # of pages charged as anon huge */ + MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ + MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */ + MEM_CGROUP_STAT_NSTATS, }; struct mem_cgroup_reclaim_cookie { @@ -233,17 +244,17 @@ static inline void mem_cgroup_end_update_page_stat(struct page *page, } void mem_cgroup_update_page_stat(struct page *page, - enum mem_cgroup_page_stat_item idx, + enum mem_cgroup_stat_index idx, int val); static inline void mem_cgroup_inc_page_stat(struct page *page, - enum mem_cgroup_page_stat_item idx) + enum mem_cgroup_stat_index idx) { mem_cgroup_update_page_stat(page, idx, 1); } static inline void mem_cgroup_dec_page_stat(struct page *page, - enum mem_cgroup_page_stat_item idx) + enum mem_cgroup_stat_index idx) { mem_cgroup_update_page_stat(page, idx, -1); } @@ -449,12 +460,12 @@ static inline bool mem_cgroup_oom_synchronize(void) } static inline void mem_cgroup_inc_page_stat(struct page *page, - enum mem_cgroup_page_stat_item idx) + enum mem_cgroup_stat_index idx) { } static inline void mem_cgroup_dec_page_stat(struct page *page, - enum mem_cgroup_page_stat_item idx) + enum mem_cgroup_stat_index idx) { } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2c71f243186e..f3803462a7e6 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -84,21 +84,6 @@ static int really_do_swap_account __initdata = 0; #endif -/* - * Statistics for memory cgroup. - */ -enum mem_cgroup_stat_index { - /* - * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. - */ - MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ - MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ - MEM_CGROUP_STAT_RSS_HUGE, /* # of pages charged as anon huge */ - MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ - MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */ - MEM_CGROUP_STAT_NSTATS, -}; - static const char * const mem_cgroup_stat_names[] = { "cache", "rss", @@ -2231,7 +2216,7 @@ void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags) } void mem_cgroup_update_page_stat(struct page *page, - enum mem_cgroup_page_stat_item idx, int val) + enum mem_cgroup_stat_index idx, int val) { struct mem_cgroup *memcg; struct page_cgroup *pc = lookup_page_cgroup(page); @@ -2244,14 +2229,6 @@ void mem_cgroup_update_page_stat(struct page *page, if (unlikely(!memcg || !PageCgroupUsed(pc))) return; - switch (idx) { - case MEMCG_NR_FILE_MAPPED: - idx = MEM_CGROUP_STAT_FILE_MAPPED; - break; - default: - BUG(); - } - this_cpu_add(memcg->stat->count[idx], val); } diff --git a/mm/rmap.c b/mm/rmap.c index 07748e68b729..a21c976a8ec1 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1111,7 +1111,7 @@ void page_add_file_rmap(struct page *page) mem_cgroup_begin_update_page_stat(page, &locked, &flags); if (atomic_inc_and_test(&page->_mapcount)) { __inc_zone_page_state(page, NR_FILE_MAPPED); - mem_cgroup_inc_page_stat(page, MEMCG_NR_FILE_MAPPED); + mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED); } mem_cgroup_end_update_page_stat(page, &locked, &flags); } @@ -1155,7 +1155,7 @@ void page_remove_rmap(struct page *page) NR_ANON_TRANSPARENT_HUGEPAGES); } else { __dec_zone_page_state(page, NR_FILE_MAPPED); - mem_cgroup_dec_page_stat(page, MEMCG_NR_FILE_MAPPED); + mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED); mem_cgroup_end_update_page_stat(page, &locked, &flags); } if (unlikely(PageMlocked(page))) -- cgit v1.2.3 From 658b72c5a7a033f0dde61b15dff86bf423ce425e Mon Sep 17 00:00:00 2001 From: Sha Zhengju Date: Thu, 12 Sep 2013 15:13:52 -0700 Subject: memcg: check for proper lock held in mem_cgroup_update_page_stat We should call mem_cgroup_begin_update_page_stat() before mem_cgroup_update_page_stat() to get proper locks, however the latter doesn't do any checking that we use proper locking, which would be hard. Suggested by Michal Hock we could at least test for rcu_read_lock_held() because RCU is held if !mem_cgroup_disabled(). Signed-off-by: Sha Zhengju Acked-by: Michal Hocko Reviewed-by: Greg Thelen Cc: Fengguang Wu Cc: KAMEZAWA Hiroyuki Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f3803462a7e6..0093bc36c5fc 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2225,6 +2225,7 @@ void mem_cgroup_update_page_stat(struct page *page, if (mem_cgroup_disabled()) return; + VM_BUG_ON(!rcu_read_lock_held()); memcg = pc->mem_cgroup; if (unlikely(!memcg || !PageCgroupUsed(pc))) return; -- cgit v1.2.3 From 3ea67d06e4679a16f69f66f43a8d6ee4778985fc Mon Sep 17 00:00:00 2001 From: Sha Zhengju Date: Thu, 12 Sep 2013 15:13:53 -0700 Subject: memcg: add per cgroup writeback pages accounting Add memcg routines to count writeback pages, later dirty pages will also be accounted. After Kame's commit 89c06bd52fb9 ("memcg: use new logic for page stat accounting"), we can use 'struct page' flag to test page state instead of per page_cgroup flag. But memcg has a feature to move a page from a cgroup to another one and may have race between "move" and "page stat accounting". So in order to avoid the race we have designed a new lock: mem_cgroup_begin_update_page_stat() modify page information -->(a) mem_cgroup_update_page_stat() -->(b) mem_cgroup_end_update_page_stat() It requires both (a) and (b)(writeback pages accounting) to be pretected in mem_cgroup_{begin/end}_update_page_stat(). It's full no-op for !CONFIG_MEMCG, almost no-op if memcg is disabled (but compiled in), rcu read lock in the most cases (no task is moving), and spin_lock_irqsave on top in the slow path. There're two writeback interfaces to modify: test_{clear/set}_page_writeback(). And the lock order is: --> memcg->move_lock --> mapping->tree_lock Signed-off-by: Sha Zhengju Acked-by: Michal Hocko Reviewed-by: Greg Thelen Cc: Fengguang Wu Cc: KAMEZAWA Hiroyuki Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 1 + mm/memcontrol.c | 30 +++++++++++++++++++++++------- mm/page-writeback.c | 15 +++++++++++++++ 3 files changed, 39 insertions(+), 7 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index f952a07ce7a9..60e95872da29 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -42,6 +42,7 @@ enum mem_cgroup_stat_index { MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ MEM_CGROUP_STAT_RSS_HUGE, /* # of pages charged as anon huge */ MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ + MEM_CGROUP_STAT_WRITEBACK, /* # of pages under writeback */ MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */ MEM_CGROUP_STAT_NSTATS, }; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0093bc36c5fc..d5ff3ce13029 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -89,6 +89,7 @@ static const char * const mem_cgroup_stat_names[] = { "rss", "rss_huge", "mapped_file", + "writeback", "swap", }; @@ -3654,6 +3655,20 @@ void mem_cgroup_split_huge_fixup(struct page *head) } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +static inline +void mem_cgroup_move_account_page_stat(struct mem_cgroup *from, + struct mem_cgroup *to, + unsigned int nr_pages, + enum mem_cgroup_stat_index idx) +{ + /* Update stat data for mem_cgroup */ + preempt_disable(); + WARN_ON_ONCE(from->stat->count[idx] < nr_pages); + __this_cpu_add(from->stat->count[idx], -nr_pages); + __this_cpu_add(to->stat->count[idx], nr_pages); + preempt_enable(); +} + /** * mem_cgroup_move_account - move account of the page * @page: the page @@ -3699,13 +3714,14 @@ static int mem_cgroup_move_account(struct page *page, move_lock_mem_cgroup(from, &flags); - if (!anon && page_mapped(page)) { - /* Update mapped_file data for mem_cgroup */ - preempt_disable(); - __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); - __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); - preempt_enable(); - } + if (!anon && page_mapped(page)) + mem_cgroup_move_account_page_stat(from, to, nr_pages, + MEM_CGROUP_STAT_FILE_MAPPED); + + if (PageWriteback(page)) + mem_cgroup_move_account_page_stat(from, to, nr_pages, + MEM_CGROUP_STAT_WRITEBACK); + mem_cgroup_charge_statistics(from, page, anon, -nr_pages); /* caller should have done css_get */ diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 6c7b0187be8e..f5236f804aa6 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2143,11 +2143,17 @@ EXPORT_SYMBOL(account_page_dirtied); /* * Helper function for set_page_writeback family. + * + * The caller must hold mem_cgroup_begin/end_update_page_stat() lock + * while calling this function. + * See test_set_page_writeback for example. + * * NOTE: Unlike account_page_dirtied this does not rely on being atomic * wrt interrupts. */ void account_page_writeback(struct page *page) { + mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_WRITEBACK); inc_zone_page_state(page, NR_WRITEBACK); } EXPORT_SYMBOL(account_page_writeback); @@ -2364,7 +2370,10 @@ int test_clear_page_writeback(struct page *page) { struct address_space *mapping = page_mapping(page); int ret; + bool locked; + unsigned long memcg_flags; + mem_cgroup_begin_update_page_stat(page, &locked, &memcg_flags); if (mapping) { struct backing_dev_info *bdi = mapping->backing_dev_info; unsigned long flags; @@ -2385,9 +2394,11 @@ int test_clear_page_writeback(struct page *page) ret = TestClearPageWriteback(page); } if (ret) { + mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_WRITEBACK); dec_zone_page_state(page, NR_WRITEBACK); inc_zone_page_state(page, NR_WRITTEN); } + mem_cgroup_end_update_page_stat(page, &locked, &memcg_flags); return ret; } @@ -2395,7 +2406,10 @@ int test_set_page_writeback(struct page *page) { struct address_space *mapping = page_mapping(page); int ret; + bool locked; + unsigned long memcg_flags; + mem_cgroup_begin_update_page_stat(page, &locked, &memcg_flags); if (mapping) { struct backing_dev_info *bdi = mapping->backing_dev_info; unsigned long flags; @@ -2422,6 +2436,7 @@ int test_set_page_writeback(struct page *page) } if (!ret) account_page_writeback(page); + mem_cgroup_end_update_page_stat(page, &locked, &memcg_flags); return ret; } -- cgit v1.2.3 From 9cb2dc1c950cf0624202c1ea2705705e1e51c278 Mon Sep 17 00:00:00 2001 From: Sha Zhengju Date: Thu, 12 Sep 2013 15:13:54 -0700 Subject: memcg: document cgroup dirty/writeback memory statistics Signed-off-by: Sha Zhengju Cc: Fengguang Wu Cc: Greg Thelen Cc: KAMEZAWA Hiroyuki Cc: Michal Hocko Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/cgroups/memory.txt | 2 ++ 1 file changed, 2 insertions(+) diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 2a3330696372..8af4ad121828 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -490,6 +490,8 @@ pgpgin - # of charging events to the memory cgroup. The charging pgpgout - # of uncharging events to the memory cgroup. The uncharging event happens each time a page is unaccounted from the cgroup. swap - # of bytes of swap usage +writeback - # of bytes of file/anon cache that are queued for syncing to + disk. inactive_anon - # of bytes of anonymous and swap cache memory on inactive LRU list. active_anon - # of bytes of anonymous and swap cache memory on active -- cgit v1.2.3 From 5fbc461636c32efdb9d5216d491d37a40d54535b Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Thu, 12 Sep 2013 15:13:55 -0700 Subject: mm: make lru_add_drain_all() selective make lru_add_drain_all() only selectively interrupt the cpus that have per-cpu free pages that can be drained. This is important in nohz mode where calling mlockall(), for example, otherwise will interrupt every core unnecessarily. This is important on workloads where nohz cores are handling 10 Gb traffic in userspace. Those CPUs do not enter the kernel and place pages into LRU pagevecs and they really, really don't want to be interrupted, or they drop packets on the floor. Signed-off-by: Chris Metcalf Reviewed-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/swap.h | 2 +- mm/swap.c | 44 +++++++++++++++++++++++++++++++++++++++----- 2 files changed, 40 insertions(+), 6 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index c03c139219c9..46ba0c6c219f 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -280,7 +280,7 @@ extern void activate_page(struct page *); extern void mark_page_accessed(struct page *); extern void lru_add_drain(void); extern void lru_add_drain_cpu(int cpu); -extern int lru_add_drain_all(void); +extern void lru_add_drain_all(void); extern void rotate_reclaimable_page(struct page *page); extern void deactivate_page(struct page *page); extern void swap_setup(void); diff --git a/mm/swap.c b/mm/swap.c index c899502d3e36..759c3caf44bd 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -432,6 +432,11 @@ static void activate_page_drain(int cpu) pagevec_lru_move_fn(pvec, __activate_page, NULL); } +static bool need_activate_page_drain(int cpu) +{ + return pagevec_count(&per_cpu(activate_page_pvecs, cpu)) != 0; +} + void activate_page(struct page *page) { if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { @@ -449,6 +454,11 @@ static inline void activate_page_drain(int cpu) { } +static bool need_activate_page_drain(int cpu) +{ + return false; +} + void activate_page(struct page *page) { struct zone *zone = page_zone(page); @@ -701,12 +711,36 @@ static void lru_add_drain_per_cpu(struct work_struct *dummy) lru_add_drain(); } -/* - * Returns 0 for success - */ -int lru_add_drain_all(void) +static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work); + +void lru_add_drain_all(void) { - return schedule_on_each_cpu(lru_add_drain_per_cpu); + static DEFINE_MUTEX(lock); + static struct cpumask has_work; + int cpu; + + mutex_lock(&lock); + get_online_cpus(); + cpumask_clear(&has_work); + + for_each_online_cpu(cpu) { + struct work_struct *work = &per_cpu(lru_add_drain_work, cpu); + + if (pagevec_count(&per_cpu(lru_add_pvec, cpu)) || + pagevec_count(&per_cpu(lru_rotate_pvecs, cpu)) || + pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) || + need_activate_page_drain(cpu)) { + INIT_WORK(work, lru_add_drain_per_cpu); + schedule_work_on(cpu, work); + cpumask_set_cpu(cpu, &has_work); + } + } + + for_each_cpu(cpu, &has_work) + flush_work(&per_cpu(lru_add_drain_work, cpu)); + + put_online_cpus(); + mutex_unlock(&lock); } /* -- cgit v1.2.3 From 7caef26767c1727d7abfbbbfbe8b2bb473430d48 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 12 Sep 2013 15:13:56 -0700 Subject: truncate: drop 'oldsize' truncate_pagecache() parameter truncate_pagecache() doesn't care about old size since commit cedabed49b39 ("vfs: Fix vmtruncate() regression"). Let's drop it. Signed-off-by: Kirill A. Shutemov Cc: OGAWA Hirofumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/adfs/inode.c | 2 +- fs/affs/file.c | 2 +- fs/bfs/file.c | 2 +- fs/btrfs/free-space-cache.c | 4 +--- fs/btrfs/inode.c | 2 +- fs/cifs/inode.c | 5 +---- fs/exofs/inode.c | 2 +- fs/ext2/inode.c | 2 +- fs/ext4/inode.c | 3 +-- fs/fat/inode.c | 2 +- fs/fuse/dir.c | 2 +- fs/fuse/inode.c | 2 +- fs/gfs2/bmap.c | 4 ++-- fs/hfs/inode.c | 2 +- fs/hfsplus/inode.c | 2 +- fs/hpfs/file.c | 2 +- fs/jfs/inode.c | 2 +- fs/minix/inode.c | 2 +- fs/nfs/inode.c | 4 +--- fs/nilfs2/inode.c | 2 +- fs/ntfs/file.c | 2 +- fs/omfs/file.c | 2 +- fs/sysv/itree.c | 2 +- fs/udf/inode.c | 2 +- fs/ufs/inode.c | 2 +- fs/xfs/xfs_aops.c | 4 ++-- include/linux/mm.h | 2 +- mm/truncate.c | 9 ++------- 28 files changed, 31 insertions(+), 44 deletions(-) diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c index 5f95d1ed9c6d..b9acadafa4a1 100644 --- a/fs/adfs/inode.c +++ b/fs/adfs/inode.c @@ -50,7 +50,7 @@ static void adfs_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); } static int adfs_write_begin(struct file *file, struct address_space *mapping, diff --git a/fs/affs/file.c b/fs/affs/file.c index 776e3935a758..8669b6ecddee 100644 --- a/fs/affs/file.c +++ b/fs/affs/file.c @@ -406,7 +406,7 @@ static void affs_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); affs_truncate(inode); } } diff --git a/fs/bfs/file.c b/fs/bfs/file.c index ad3ea1497cc3..ae2892218335 100644 --- a/fs/bfs/file.c +++ b/fs/bfs/file.c @@ -166,7 +166,7 @@ static void bfs_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); } static int bfs_write_begin(struct file *file, struct address_space *mapping, diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index b21a3cd667d8..256d9597f0cf 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -221,12 +221,10 @@ int btrfs_truncate_free_space_cache(struct btrfs_root *root, struct btrfs_path *path, struct inode *inode) { - loff_t oldsize; int ret = 0; - oldsize = i_size_read(inode); btrfs_i_size_write(inode, 0); - truncate_pagecache(inode, oldsize, 0); + truncate_pagecache(inode, 0); /* * We don't need an orphan item because truncating the free space cache diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 7bdc83d04d54..82fdd7059d10 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4409,7 +4409,7 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr) inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb); if (newsize > oldsize) { - truncate_pagecache(inode, oldsize, newsize); + truncate_pagecache(inode, newsize); ret = btrfs_cont_expand(inode, oldsize, newsize); if (ret) return ret; diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index 449b6cf09b09..2a92c5c6ecfd 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -1852,14 +1852,11 @@ static int cifs_truncate_page(struct address_space *mapping, loff_t from) static void cifs_setsize(struct inode *inode, loff_t offset) { - loff_t oldsize; - spin_lock(&inode->i_lock); - oldsize = inode->i_size; i_size_write(inode, offset); spin_unlock(&inode->i_lock); - truncate_pagecache(inode, oldsize, offset); + truncate_pagecache(inode, offset); } static int diff --git a/fs/exofs/inode.c b/fs/exofs/inode.c index 2ec8eb1ab269..a52a5d23c30b 100644 --- a/fs/exofs/inode.c +++ b/fs/exofs/inode.c @@ -861,7 +861,7 @@ static int exofs_writepage(struct page *page, struct writeback_control *wbc) static void _write_failed(struct inode *inode, loff_t to) { if (to > inode->i_size) - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); } int exofs_write_begin(struct file *file, struct address_space *mapping, diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 0a87bb10998d..c260de6d7b6d 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -58,7 +58,7 @@ static void ext2_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); ext2_truncate_blocks(inode, inode->i_size); } } diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c79fd7dabe79..0d424d7ac02b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4587,7 +4587,6 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) if (attr->ia_valid & ATTR_SIZE && attr->ia_size != inode->i_size) { handle_t *handle; - loff_t oldsize = inode->i_size; if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); @@ -4650,7 +4649,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) * Truncate pagecache after we've waited for commit * in data=journal mode to make pages freeable. */ - truncate_pagecache(inode, oldsize, inode->i_size); + truncate_pagecache(inode, inode->i_size); } /* * We want to call ext4_truncate() even if attr->ia_size == diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 11b51bb55b42..0062da21dd8b 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -147,7 +147,7 @@ static void fat_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); fat_truncate_blocks(inode, inode->i_size); } } diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 3ac91086f41f..62b43b577bfc 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1678,7 +1678,7 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr, * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. */ if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { - truncate_pagecache(inode, oldsize, outarg.attr.size); + truncate_pagecache(inode, outarg.attr.size); invalidate_inode_pages2(inode->i_mapping); } diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 84434594e80e..a8ce6dab60a0 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -218,7 +218,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, bool inval = false; if (oldsize != attr->size) { - truncate_pagecache(inode, oldsize, attr->size); + truncate_pagecache(inode, attr->size); inval = true; } else if (fc->auto_inval_data) { struct timespec new_mtime = { diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 5e2f56fccf6b..62a65fc448dc 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -1016,7 +1016,7 @@ static int gfs2_journaled_truncate(struct inode *inode, u64 oldsize, u64 newsize chunk = oldsize - newsize; if (chunk > max_chunk) chunk = max_chunk; - truncate_pagecache(inode, oldsize, oldsize - chunk); + truncate_pagecache(inode, oldsize - chunk); oldsize -= chunk; gfs2_trans_end(sdp); error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES); @@ -1067,7 +1067,7 @@ static int trunc_start(struct inode *inode, u64 oldsize, u64 newsize) if (journaled) error = gfs2_journaled_truncate(inode, oldsize, newsize); else - truncate_pagecache(inode, oldsize, newsize); + truncate_pagecache(inode, newsize); if (error) { brelse(dibh); diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c index f9299d8a64e3..380ab31b5e0f 100644 --- a/fs/hfs/inode.c +++ b/fs/hfs/inode.c @@ -41,7 +41,7 @@ static void hfs_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); hfs_file_truncate(inode); } } diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c index 4d2edaea891c..37213d075f3c 100644 --- a/fs/hfsplus/inode.c +++ b/fs/hfsplus/inode.c @@ -36,7 +36,7 @@ static void hfsplus_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); hfsplus_file_truncate(inode); } } diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c index 4e9dabcf1f4c..67c1a61e0955 100644 --- a/fs/hpfs/file.c +++ b/fs/hpfs/file.c @@ -138,7 +138,7 @@ static void hpfs_write_failed(struct address_space *mapping, loff_t to) hpfs_lock(inode->i_sb); if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); hpfs_truncate(inode); } diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c index 730f24e282a6..f4aab719add5 100644 --- a/fs/jfs/inode.c +++ b/fs/jfs/inode.c @@ -306,7 +306,7 @@ static void jfs_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); jfs_truncate(inode); } } diff --git a/fs/minix/inode.c b/fs/minix/inode.c index df122496f328..0332109162a5 100644 --- a/fs/minix/inode.c +++ b/fs/minix/inode.c @@ -400,7 +400,7 @@ static void minix_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); minix_truncate(inode); } } diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 87e797640828..eda8879171c4 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -541,7 +541,6 @@ EXPORT_SYMBOL_GPL(nfs_setattr); */ static int nfs_vmtruncate(struct inode * inode, loff_t offset) { - loff_t oldsize; int err; err = inode_newsize_ok(inode, offset); @@ -549,11 +548,10 @@ static int nfs_vmtruncate(struct inode * inode, loff_t offset) goto out; spin_lock(&inode->i_lock); - oldsize = inode->i_size; i_size_write(inode, offset); spin_unlock(&inode->i_lock); - truncate_pagecache(inode, oldsize, offset); + truncate_pagecache(inode, offset); out: return err; } diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index b1a5277cfd18..7e350c562e0e 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -254,7 +254,7 @@ void nilfs_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); nilfs_truncate(inode); } } diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index c5670b8d198c..ea4ba9daeb47 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -1768,7 +1768,7 @@ static void ntfs_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); ntfs_truncate_vfs(inode); } } diff --git a/fs/omfs/file.c b/fs/omfs/file.c index e0d9b3e722bd..54d57d6ba68d 100644 --- a/fs/omfs/file.c +++ b/fs/omfs/file.c @@ -311,7 +311,7 @@ static void omfs_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); omfs_truncate(inode); } } diff --git a/fs/sysv/itree.c b/fs/sysv/itree.c index c1a591a4725b..66bc316927e8 100644 --- a/fs/sysv/itree.c +++ b/fs/sysv/itree.c @@ -469,7 +469,7 @@ static void sysv_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) { - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); sysv_truncate(inode); } } diff --git a/fs/udf/inode.c b/fs/udf/inode.c index b6d15d349810..062b7925bca0 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -172,7 +172,7 @@ static void udf_write_failed(struct address_space *mapping, loff_t to) loff_t isize = inode->i_size; if (to > isize) { - truncate_pagecache(inode, to, isize); + truncate_pagecache(inode, isize); if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) { down_write(&iinfo->i_data_sem); udf_clear_extent_cache(inode); diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c index ff24e4449ece..c8ca96086784 100644 --- a/fs/ufs/inode.c +++ b/fs/ufs/inode.c @@ -531,7 +531,7 @@ static void ufs_write_failed(struct address_space *mapping, loff_t to) struct inode *inode = mapping->host; if (to > inode->i_size) - truncate_pagecache(inode, to, inode->i_size); + truncate_pagecache(inode, inode->i_size); } static int ufs_write_begin(struct file *file, struct address_space *mapping, diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 977da0ec6604..e51e581454e9 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -1582,7 +1582,7 @@ xfs_vm_write_begin( unlock_page(page); if (pos + len > i_size_read(inode)) - truncate_pagecache(inode, pos + len, i_size_read(inode)); + truncate_pagecache(inode, i_size_read(inode)); page_cache_release(page); page = NULL; @@ -1618,7 +1618,7 @@ xfs_vm_write_end( loff_t to = pos + len; if (to > isize) { - truncate_pagecache(inode, to, isize); + truncate_pagecache(inode, isize); xfs_vm_kill_delalloc_range(inode, isize, to); } } diff --git a/include/linux/mm.h b/include/linux/mm.h index 3d9b503bcd00..928df792c005 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -985,7 +985,7 @@ static inline void unmap_shared_mapping_range(struct address_space *mapping, unmap_mapping_range(mapping, holebegin, holelen, 0); } -extern void truncate_pagecache(struct inode *inode, loff_t old, loff_t new); +extern void truncate_pagecache(struct inode *inode, loff_t new); extern void truncate_setsize(struct inode *inode, loff_t newsize); void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end); int truncate_inode_page(struct address_space *mapping, struct page *page); diff --git a/mm/truncate.c b/mm/truncate.c index e2e8a8a7eb9d..353b683afd6e 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -567,7 +567,6 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages2); /** * truncate_pagecache - unmap and remove pagecache that has been truncated * @inode: inode - * @oldsize: old file size * @newsize: new file size * * inode's new i_size must already be written before truncate_pagecache @@ -580,7 +579,7 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages2); * situations such as writepage being called for a page that has already * had its underlying blocks deallocated. */ -void truncate_pagecache(struct inode *inode, loff_t oldsize, loff_t newsize) +void truncate_pagecache(struct inode *inode, loff_t newsize) { struct address_space *mapping = inode->i_mapping; loff_t holebegin = round_up(newsize, PAGE_SIZE); @@ -614,12 +613,8 @@ EXPORT_SYMBOL(truncate_pagecache); */ void truncate_setsize(struct inode *inode, loff_t newsize) { - loff_t oldsize; - - oldsize = inode->i_size; i_size_write(inode, newsize); - - truncate_pagecache(inode, oldsize, newsize); + truncate_pagecache(inode, newsize); } EXPORT_SYMBOL(truncate_setsize); -- cgit v1.2.3 From 3cd14fcd3f128d5eba8575491cb4e1999ee1bad2 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 12 Sep 2013 15:13:58 -0700 Subject: thp: account anon transparent huge pages into NR_ANON_PAGES We use NR_ANON_PAGES as base for reporting AnonPages to user. There's not much sense in not accounting transparent huge pages there, but add them on printing to user. Let's account transparent huge pages in NR_ANON_PAGES in the first place. Signed-off-by: Kirill A. Shutemov Acked-by: Dave Hansen Cc: Andrea Arcangeli Cc: Al Viro Cc: Hugh Dickins Cc: Wu Fengguang Cc: Jan Kara Cc: Mel Gorman Cc: Andi Kleen Cc: Matthew Wilcox Cc: Hillf Danton Cc: Ning Qu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/node.c | 6 ------ fs/proc/meminfo.c | 6 ------ mm/huge_memory.c | 1 - mm/rmap.c | 18 +++++++++--------- 4 files changed, 9 insertions(+), 22 deletions(-) diff --git a/drivers/base/node.c b/drivers/base/node.c index 7616a77ca322..bc9f43bf7e29 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -125,13 +125,7 @@ static ssize_t node_read_meminfo(struct device *dev, nid, K(node_page_state(nid, NR_WRITEBACK)), nid, K(node_page_state(nid, NR_FILE_PAGES)), nid, K(node_page_state(nid, NR_FILE_MAPPED)), -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - nid, K(node_page_state(nid, NR_ANON_PAGES) - + node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) * - HPAGE_PMD_NR), -#else nid, K(node_page_state(nid, NR_ANON_PAGES)), -#endif nid, K(node_page_state(nid, NR_SHMEM)), nid, node_page_state(nid, NR_KERNEL_STACK) * THREAD_SIZE / 1024, diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c index 5aa847a603c0..59d85d608898 100644 --- a/fs/proc/meminfo.c +++ b/fs/proc/meminfo.c @@ -132,13 +132,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v) K(i.freeswap), K(global_page_state(NR_FILE_DIRTY)), K(global_page_state(NR_WRITEBACK)), -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - K(global_page_state(NR_ANON_PAGES) - + global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) * - HPAGE_PMD_NR), -#else K(global_page_state(NR_ANON_PAGES)), -#endif K(global_page_state(NR_FILE_MAPPED)), K(global_page_state(NR_SHMEM)), K(global_page_state(NR_SLAB_RECLAIMABLE) + diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 963e14c0486f..7cef0c098630 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1661,7 +1661,6 @@ static void __split_huge_page_refcount(struct page *page, BUG_ON(atomic_read(&page->_count) <= 0); __mod_zone_page_state(zone, NR_ANON_TRANSPARENT_HUGEPAGES, -1); - __mod_zone_page_state(zone, NR_ANON_PAGES, HPAGE_PMD_NR); ClearPageCompound(page); compound_unlock(page); diff --git a/mm/rmap.c b/mm/rmap.c index a21c976a8ec1..fd3ee7a54a13 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1052,11 +1052,11 @@ void do_page_add_anon_rmap(struct page *page, { int first = atomic_inc_and_test(&page->_mapcount); if (first) { - if (!PageTransHuge(page)) - __inc_zone_page_state(page, NR_ANON_PAGES); - else + if (PageTransHuge(page)) __inc_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES); + __mod_zone_page_state(page_zone(page), NR_ANON_PAGES, + hpage_nr_pages(page)); } if (unlikely(PageKsm(page))) return; @@ -1085,10 +1085,10 @@ void page_add_new_anon_rmap(struct page *page, VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end); SetPageSwapBacked(page); atomic_set(&page->_mapcount, 0); /* increment count (starts at -1) */ - if (!PageTransHuge(page)) - __inc_zone_page_state(page, NR_ANON_PAGES); - else + if (PageTransHuge(page)) __inc_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES); + __mod_zone_page_state(page_zone(page), NR_ANON_PAGES, + hpage_nr_pages(page)); __page_set_anon_rmap(page, vma, address, 1); if (!mlocked_vma_newpage(vma, page)) { SetPageActive(page); @@ -1148,11 +1148,11 @@ void page_remove_rmap(struct page *page) goto out; if (anon) { mem_cgroup_uncharge_page(page); - if (!PageTransHuge(page)) - __dec_zone_page_state(page, NR_ANON_PAGES); - else + if (PageTransHuge(page)) __dec_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES); + __mod_zone_page_state(page_zone(page), NR_ANON_PAGES, + -hpage_nr_pages(page)); } else { __dec_zone_page_state(page, NR_FILE_MAPPED); mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED); -- cgit v1.2.3 From 66a0c8ee3dce78362d59f00a8efbd752fbeddfb1 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 12 Sep 2013 15:13:59 -0700 Subject: mm: cleanup add_to_page_cache_locked() Make add_to_page_cache_locked() cleaner: - unindent most code of the function by inverting one condition; - streamline code no-error path; - move insert error path outside normal code path; - call radix_tree_preload_end() earlier; No functional changes. Signed-off-by: Kirill A. Shutemov Acked-by: Dave Hansen Cc: Andrea Arcangeli Cc: Al Viro Cc: Hugh Dickins Cc: Wu Fengguang Cc: Jan Kara Cc: Mel Gorman Cc: Andi Kleen Cc: Matthew Wilcox Cc: Hillf Danton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/filemap.c | 48 +++++++++++++++++++++++++----------------------- 1 file changed, 25 insertions(+), 23 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index e3b6fc8c0b7b..1e6aec4a2d2e 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -467,32 +467,34 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping, error = mem_cgroup_cache_charge(page, current->mm, gfp_mask & GFP_RECLAIM_MASK); if (error) - goto out; + return error; error = radix_tree_maybe_preload(gfp_mask & ~__GFP_HIGHMEM); - if (error == 0) { - page_cache_get(page); - page->mapping = mapping; - page->index = offset; - - spin_lock_irq(&mapping->tree_lock); - error = radix_tree_insert(&mapping->page_tree, offset, page); - if (likely(!error)) { - mapping->nrpages++; - __inc_zone_page_state(page, NR_FILE_PAGES); - spin_unlock_irq(&mapping->tree_lock); - trace_mm_filemap_add_to_page_cache(page); - } else { - page->mapping = NULL; - /* Leave page->index set: truncation relies upon it */ - spin_unlock_irq(&mapping->tree_lock); - mem_cgroup_uncharge_cache_page(page); - page_cache_release(page); - } - radix_tree_preload_end(); - } else + if (error) { mem_cgroup_uncharge_cache_page(page); -out: + return error; + } + + page_cache_get(page); + page->mapping = mapping; + page->index = offset; + + spin_lock_irq(&mapping->tree_lock); + error = radix_tree_insert(&mapping->page_tree, offset, page); + radix_tree_preload_end(); + if (unlikely(error)) + goto err_insert; + mapping->nrpages++; + __inc_zone_page_state(page, NR_FILE_PAGES); + spin_unlock_irq(&mapping->tree_lock); + trace_mm_filemap_add_to_page_cache(page); + return 0; +err_insert: + page->mapping = NULL; + /* Leave page->index set: truncation relies upon it */ + spin_unlock_irq(&mapping->tree_lock); + mem_cgroup_uncharge_cache_page(page); + page_cache_release(page); return error; } EXPORT_SYMBOL(add_to_page_cache_locked); -- cgit v1.2.3 From 3122359a64829afd231bad6ed899b557f46280e9 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 12 Sep 2013 15:14:01 -0700 Subject: thp: move maybe_pmd_mkwrite() out of mk_huge_pmd() It's confusing that mk_huge_pmd() has semantics different from mk_pte() or mk_pmd(). I spent some time on debugging issue cased by this inconsistency. Let's move maybe_pmd_mkwrite() out of mk_huge_pmd() and adjust prototype to match mk_pte(). Signed-off-by: Kirill A. Shutemov Acked-by: Dave Hansen Cc: Andrea Arcangeli Cc: Al Viro Cc: Hugh Dickins Cc: Wu Fengguang Cc: Jan Kara Cc: Mel Gorman Cc: Andi Kleen Cc: Matthew Wilcox Cc: Hillf Danton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 7cef0c098630..60836870c6f7 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -690,11 +690,10 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) return pmd; } -static inline pmd_t mk_huge_pmd(struct page *page, struct vm_area_struct *vma) +static inline pmd_t mk_huge_pmd(struct page *page, pgprot_t prot) { pmd_t entry; - entry = mk_pmd(page, vma->vm_page_prot); - entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); + entry = mk_pmd(page, prot); entry = pmd_mkhuge(entry); return entry; } @@ -727,7 +726,8 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm, pte_free(mm, pgtable); } else { pmd_t entry; - entry = mk_huge_pmd(page, vma); + entry = mk_huge_pmd(page, vma->vm_page_prot); + entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); page_add_new_anon_rmap(page, vma, haddr); pgtable_trans_huge_deposit(mm, pmd, pgtable); set_pmd_at(mm, haddr, pmd, entry); @@ -1210,7 +1210,8 @@ alloc: goto out_mn; } else { pmd_t entry; - entry = mk_huge_pmd(new_page, vma); + entry = mk_huge_pmd(new_page, vma->vm_page_prot); + entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); pmdp_clear_flush(vma, haddr, pmd); page_add_new_anon_rmap(new_page, vma, haddr); set_pmd_at(mm, haddr, pmd, entry); @@ -2358,7 +2359,8 @@ static void collapse_huge_page(struct mm_struct *mm, __SetPageUptodate(new_page); pgtable = pmd_pgtable(_pmd); - _pmd = mk_huge_pmd(new_page, vma); + _pmd = mk_huge_pmd(new_page, vma->vm_page_prot); + _pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma); /* * spin_lock() below is not the equivalent of smp_wmb(), so -- cgit v1.2.3 From 128ec037bafe5905b2e6f2796f426a1d247d0066 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 12 Sep 2013 15:14:03 -0700 Subject: thp: do_huge_pmd_anonymous_page() cleanup Minor cleanup: unindent most code of the fucntion by inverting one condition. It's preparation for the next patch. No functional changes. Signed-off-by: Kirill A. Shutemov Acked-by: Hillf Danton Cc: Andrea Arcangeli Cc: Al Viro Cc: Hugh Dickins Cc: Wu Fengguang Cc: Jan Kara Cc: Mel Gorman Cc: Andi Kleen Cc: Matthew Wilcox Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 83 ++++++++++++++++++++++++++++---------------------------- 1 file changed, 41 insertions(+), 42 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 60836870c6f7..6551dd06dd64 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -785,55 +785,54 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long haddr = address & HPAGE_PMD_MASK; pte_t *pte; - if (haddr >= vma->vm_start && haddr + HPAGE_PMD_SIZE <= vma->vm_end) { - if (unlikely(anon_vma_prepare(vma))) - return VM_FAULT_OOM; - if (unlikely(khugepaged_enter(vma))) + if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end) + goto out; + if (unlikely(anon_vma_prepare(vma))) + return VM_FAULT_OOM; + if (unlikely(khugepaged_enter(vma))) + return VM_FAULT_OOM; + if (!(flags & FAULT_FLAG_WRITE) && + transparent_hugepage_use_zero_page()) { + pgtable_t pgtable; + struct page *zero_page; + bool set; + pgtable = pte_alloc_one(mm, haddr); + if (unlikely(!pgtable)) return VM_FAULT_OOM; - if (!(flags & FAULT_FLAG_WRITE) && - transparent_hugepage_use_zero_page()) { - pgtable_t pgtable; - struct page *zero_page; - bool set; - pgtable = pte_alloc_one(mm, haddr); - if (unlikely(!pgtable)) - return VM_FAULT_OOM; - zero_page = get_huge_zero_page(); - if (unlikely(!zero_page)) { - pte_free(mm, pgtable); - count_vm_event(THP_FAULT_FALLBACK); - goto out; - } - spin_lock(&mm->page_table_lock); - set = set_huge_zero_page(pgtable, mm, vma, haddr, pmd, - zero_page); - spin_unlock(&mm->page_table_lock); - if (!set) { - pte_free(mm, pgtable); - put_huge_zero_page(); - } - return 0; - } - page = alloc_hugepage_vma(transparent_hugepage_defrag(vma), - vma, haddr, numa_node_id(), 0); - if (unlikely(!page)) { + zero_page = get_huge_zero_page(); + if (unlikely(!zero_page)) { + pte_free(mm, pgtable); count_vm_event(THP_FAULT_FALLBACK); goto out; } - count_vm_event(THP_FAULT_ALLOC); - if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) { - put_page(page); - goto out; - } - if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, - page))) { - mem_cgroup_uncharge_page(page); - put_page(page); - goto out; + spin_lock(&mm->page_table_lock); + set = set_huge_zero_page(pgtable, mm, vma, haddr, pmd, + zero_page); + spin_unlock(&mm->page_table_lock); + if (!set) { + pte_free(mm, pgtable); + put_huge_zero_page(); } - return 0; } + page = alloc_hugepage_vma(transparent_hugepage_defrag(vma), + vma, haddr, numa_node_id(), 0); + if (unlikely(!page)) { + count_vm_event(THP_FAULT_FALLBACK); + goto out; + } + count_vm_event(THP_FAULT_ALLOC); + if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) { + put_page(page); + goto out; + } + if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page))) { + mem_cgroup_uncharge_page(page); + put_page(page); + goto out; + } + + return 0; out: /* * Use __pte_alloc instead of pte_alloc_map, because we can't -- cgit v1.2.3 From c02925540ca7019465a43c00f8a3c0186ddace2b Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 12 Sep 2013 15:14:05 -0700 Subject: thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page() do_huge_pmd_anonymous_page() has copy-pasted piece of handle_mm_fault() to handle fallback path. Let's consolidate code back by introducing VM_FAULT_FALLBACK return code. Signed-off-by: Kirill A. Shutemov Acked-by: Hillf Danton Cc: Andrea Arcangeli Cc: Al Viro Cc: Hugh Dickins Cc: Wu Fengguang Cc: Jan Kara Cc: Mel Gorman Cc: Andi Kleen Cc: Matthew Wilcox Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/huge_mm.h | 3 --- include/linux/mm.h | 3 ++- mm/huge_memory.c | 31 +++++-------------------------- mm/memory.c | 9 ++++++--- 4 files changed, 13 insertions(+), 33 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index b60de92e2edc..3935428c57cf 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -96,9 +96,6 @@ extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma, unsigned long addr, unsigned long end); -extern int handle_pte_fault(struct mm_struct *mm, - struct vm_area_struct *vma, unsigned long address, - pte_t *pte, pmd_t *pmd, unsigned int flags); extern int split_huge_page_to_list(struct page *page, struct list_head *list); static inline int split_huge_page(struct page *page) { diff --git a/include/linux/mm.h b/include/linux/mm.h index 928df792c005..8b6e55ee8855 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -877,11 +877,12 @@ static inline int page_mapped(struct page *page) #define VM_FAULT_NOPAGE 0x0100 /* ->fault installed the pte, not return page */ #define VM_FAULT_LOCKED 0x0200 /* ->fault locked the returned page */ #define VM_FAULT_RETRY 0x0400 /* ->fault blocked, must retry */ +#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */ #define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */ #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | \ - VM_FAULT_HWPOISON_LARGE) + VM_FAULT_FALLBACK | VM_FAULT_HWPOISON_LARGE) /* Encode hstate index for a hwpoisoned large page */ #define VM_FAULT_SET_HINDEX(x) ((x) << 12) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 6551dd06dd64..243f4cc75777 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -783,10 +783,9 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, { struct page *page; unsigned long haddr = address & HPAGE_PMD_MASK; - pte_t *pte; if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end) - goto out; + return VM_FAULT_FALLBACK; if (unlikely(anon_vma_prepare(vma))) return VM_FAULT_OOM; if (unlikely(khugepaged_enter(vma))) @@ -803,7 +802,7 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, if (unlikely(!zero_page)) { pte_free(mm, pgtable); count_vm_event(THP_FAULT_FALLBACK); - goto out; + return VM_FAULT_FALLBACK; } spin_lock(&mm->page_table_lock); set = set_huge_zero_page(pgtable, mm, vma, haddr, pmd, @@ -819,40 +818,20 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, vma, haddr, numa_node_id(), 0); if (unlikely(!page)) { count_vm_event(THP_FAULT_FALLBACK); - goto out; + return VM_FAULT_FALLBACK; } count_vm_event(THP_FAULT_ALLOC); if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) { put_page(page); - goto out; + return VM_FAULT_FALLBACK; } if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page))) { mem_cgroup_uncharge_page(page); put_page(page); - goto out; + return VM_FAULT_FALLBACK; } return 0; -out: - /* - * Use __pte_alloc instead of pte_alloc_map, because we can't - * run pte_offset_map on the pmd, if an huge pmd could - * materialize from under us from a different thread. - */ - if (unlikely(pmd_none(*pmd)) && - unlikely(__pte_alloc(mm, vma, pmd, address))) - return VM_FAULT_OOM; - /* if an huge pmd materialized from under us just retry later */ - if (unlikely(pmd_trans_huge(*pmd))) - return 0; - /* - * A regular pmd is established and it can't morph into a huge pmd - * from under us anymore at this point because we hold the mmap_sem - * read mode and khugepaged takes it in write mode. So now it's - * safe to run pte_offset_map(). - */ - pte = pte_offset_map(pmd, address); - return handle_pte_fault(mm, vma, address, pte, pmd, flags); } int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, diff --git a/mm/memory.c b/mm/memory.c index 5ec6f199e685..ca0003947115 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3695,7 +3695,7 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, * but allow concurrent faults), and pte mapped but not yet locked. * We return with mmap_sem still held, but pte unmapped and unlocked. */ -int handle_pte_fault(struct mm_struct *mm, +static int handle_pte_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *pte, pmd_t *pmd, unsigned int flags) { @@ -3774,9 +3774,12 @@ retry: if (!pmd) return VM_FAULT_OOM; if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) { + int ret = VM_FAULT_FALLBACK; if (!vma->vm_ops) - return do_huge_pmd_anonymous_page(mm, vma, address, - pmd, flags); + ret = do_huge_pmd_anonymous_page(mm, vma, address, + pmd, flags); + if (!(ret & VM_FAULT_FALLBACK)) + return ret; } else { pmd_t orig_pmd = *pmd; int ret; -- cgit v1.2.3 From 17766dde364813568e4f876517c72bab70838646 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Thu, 12 Sep 2013 15:14:06 -0700 Subject: mm, thp: count thp_fault_fallback anytime thp fault fails Currently, thp_fault_fallback in vmstat only gets incremented if a hugepage allocation fails. If current's memcg hits its limit or the page fault handler returns an error, it is incorrectly accounted as a successful thp_fault_alloc. Count thp_fault_fallback anytime the page fault handler falls back to using regular pages and only count thp_fault_alloc when a hugepage has actually been faulted. Signed-off-by: David Rientjes Cc: Mel Gorman Cc: Andrea Arcangeli Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 243f4cc75777..f60c4ebaa30c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -820,17 +820,19 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; } - count_vm_event(THP_FAULT_ALLOC); if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) { put_page(page); + count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; } if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page))) { mem_cgroup_uncharge_page(page); put_page(page); + count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; } + count_vm_event(THP_FAULT_ALLOC); return 0; } @@ -1143,7 +1145,6 @@ alloc: new_page = NULL; if (unlikely(!new_page)) { - count_vm_event(THP_FAULT_FALLBACK); if (is_huge_zero_pmd(orig_pmd)) { ret = do_huge_pmd_wp_zero_page_fallback(mm, vma, address, pmd, orig_pmd, haddr); @@ -1154,9 +1155,9 @@ alloc: split_huge_page(page); put_page(page); } + count_vm_event(THP_FAULT_FALLBACK); goto out; } - count_vm_event(THP_FAULT_ALLOC); if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) { put_page(new_page); @@ -1164,10 +1165,13 @@ alloc: split_huge_page(page); put_page(page); } + count_vm_event(THP_FAULT_FALLBACK); ret |= VM_FAULT_OOM; goto out; } + count_vm_event(THP_FAULT_ALLOC); + if (is_huge_zero_pmd(orig_pmd)) clear_huge_page(new_page, haddr, HPAGE_PMD_NR); else -- cgit v1.2.3 From 6072ddc8520b86adfac6939ca32fb6e6c4de017a Mon Sep 17 00:00:00 2001 From: Jingoo Han Date: Thu, 12 Sep 2013 15:14:07 -0700 Subject: kernel: replace strict_strto*() with kstrto*() The usage of strict_strto*() is not preferred, because strict_strto*() is obsolete. Thus, kstrto*() should be used. Signed-off-by: Jingoo Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/gcov/fs.c | 2 +- kernel/ksysfs.c | 2 +- kernel/params.c | 14 +++++++------- 3 files changed, 9 insertions(+), 9 deletions(-) diff --git a/kernel/gcov/fs.c b/kernel/gcov/fs.c index 9bd0934f6c33..7a7d2ee96d42 100644 --- a/kernel/gcov/fs.c +++ b/kernel/gcov/fs.c @@ -74,7 +74,7 @@ static int __init gcov_persist_setup(char *str) { unsigned long val; - if (strict_strtoul(str, 0, &val)) { + if (kstrtoul(str, 0, &val)) { pr_warning("invalid gcov_persist parameter '%s'\n", str); return 0; } diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 6ada93c23a9a..9659d38e008f 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -113,7 +113,7 @@ static ssize_t kexec_crash_size_store(struct kobject *kobj, unsigned long cnt; int ret; - if (strict_strtoul(buf, 0, &cnt)) + if (kstrtoul(buf, 0, &cnt)) return -EINVAL; ret = crash_shrink_memory(cnt); diff --git a/kernel/params.c b/kernel/params.c index 501bde4f3bee..81c4e78c8f4c 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -253,13 +253,13 @@ int parse_args(const char *doing, EXPORT_SYMBOL(param_ops_##name) -STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", unsigned long, strict_strtoul); -STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol); -STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul); -STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol); -STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul); -STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol); -STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul); +STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", unsigned long, kstrtoul); +STANDARD_PARAM_DEF(short, short, "%hi", long, kstrtoul); +STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, kstrtoul); +STANDARD_PARAM_DEF(int, int, "%i", long, kstrtoul); +STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, kstrtoul); +STANDARD_PARAM_DEF(long, long, "%li", long, kstrtoul); +STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, kstrtoul); int param_set_charp(const char *val, const struct kernel_param *kp) { -- cgit v1.2.3 From de32a8177f64bc62e1b19c685dd391af664ab13f Mon Sep 17 00:00:00 2001 From: Chen Gang Date: Thu, 12 Sep 2013 15:14:08 -0700 Subject: mm/Kconfig: add MMU dependency for MIGRATION. MIGRATION must depend on MMU, or allmodconfig for the nommu sh architecture fails to build: CC mm/migrate.o mm/migrate.c: In function 'remove_migration_pte': mm/migrate.c:134:3: error: implicit declaration of function 'pmd_trans_huge' [-Werror=implicit-function-declaration] if (pmd_trans_huge(*pmd)) ^ mm/migrate.c:149:2: error: implicit declaration of function 'is_swap_pte' [-Werror=implicit-function-declaration] if (!is_swap_pte(pte)) ^ ... Also let CMA depend on MMU, or when NOMMU, if we select CMA, it will select MIGRATION by force. Signed-off-by: Chen Gang Reviewed-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/Kconfig b/mm/Kconfig index 6cdd27043303..026771a9b097 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -245,7 +245,7 @@ config COMPACTION config MIGRATION bool "Page migration" def_bool y - depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA + depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU help Allows the migration of the physical location of pages of processes while the virtual addresses are not changed. This is useful in @@ -480,7 +480,7 @@ config FRONTSWAP config CMA bool "Contiguous Memory Allocator" - depends on HAVE_MEMBLOCK + depends on HAVE_MEMBLOCK && MMU select MIGRATION select MEMORY_ISOLATION help -- cgit v1.2.3