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author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2012-05-29 15:07:03 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-29 16:22:27 -0700 |
commit | d01dd17f1067ca50dbb9d1d3400d33221ce339e7 (patch) | |
tree | 07c8f7da424666c7fd81bb4a5b8288e68b87d094 /mm | |
parent | 2bb2ba9d51a8044a71a29608d2c4ef8f5b2d57a2 (diff) | |
download | lwn-d01dd17f1067ca50dbb9d1d3400d33221ce339e7.tar.gz lwn-d01dd17f1067ca50dbb9d1d3400d33221ce339e7.zip |
memcg: use res_counter_uncharge_until() in move_parent()
By using res_counter_uncharge_until(), we can avoid race and unnecessary
charging.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ying Han <yinghan@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/memcontrol.c | 42 |
1 files changed, 36 insertions, 6 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9d1764630dff..1262a8bc402b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2423,6 +2423,24 @@ static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, } /* + * Cancel chrages in this cgroup....doesn't propagate to parent cgroup. + * This is useful when moving usage to parent cgroup. + */ +static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, + unsigned int nr_pages) +{ + unsigned long bytes = nr_pages * PAGE_SIZE; + + if (mem_cgroup_is_root(memcg)) + return; + + res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes); + if (do_swap_account) + res_counter_uncharge_until(&memcg->memsw, + memcg->memsw.parent, bytes); +} + +/* * A helper function to get mem_cgroup from ID. must be called under * rcu_read_lock(). The caller must check css_is_removed() or some if * it's concern. (dropping refcnt from swap can be called against removed @@ -2680,16 +2698,28 @@ static int mem_cgroup_move_parent(struct page *page, nr_pages = hpage_nr_pages(page); parent = mem_cgroup_from_cont(pcg); - ret = __mem_cgroup_try_charge(NULL, gfp_mask, nr_pages, &parent, false); - if (ret) - goto put_back; + if (!parent->use_hierarchy) { + ret = __mem_cgroup_try_charge(NULL, + gfp_mask, nr_pages, &parent, false); + if (ret) + goto put_back; + } if (nr_pages > 1) flags = compound_lock_irqsave(page); - ret = mem_cgroup_move_account(page, nr_pages, pc, child, parent, true); - if (ret) - __mem_cgroup_cancel_charge(parent, nr_pages); + if (parent->use_hierarchy) { + ret = mem_cgroup_move_account(page, nr_pages, + pc, child, parent, false); + if (!ret) + __mem_cgroup_cancel_local_charge(child, nr_pages); + } else { + ret = mem_cgroup_move_account(page, nr_pages, + pc, child, parent, true); + + if (ret) + __mem_cgroup_cancel_charge(parent, nr_pages); + } if (nr_pages > 1) compound_unlock_irqrestore(page, flags); |