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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-11-02 19:38:47 -1000 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-11-02 19:38:47 -1000 |
commit | ecae0bd5173b1014f95a14a8dfbe40ec10367dcf (patch) | |
tree | f571213ef1a35354ea79f0240a180fdb4111b290 /mm/vmscan.c | |
parent | bc3012f4e3a9765de81f454cb8f9bb16aafc6ff5 (diff) | |
parent | 9732336006764e2ee61225387e3c70eae9139035 (diff) | |
download | lwn-ecae0bd5173b1014f95a14a8dfbe40ec10367dcf.tar.gz lwn-ecae0bd5173b1014f95a14a8dfbe40ec10367dcf.zip |
Merge tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Many singleton patches against the MM code. The patch series which are
included in this merge do the following:
- Kemeng Shi has contributed some compation maintenance work in the
series 'Fixes and cleanups to compaction'
- Joel Fernandes has a patchset ('Optimize mremap during mutual
alignment within PMD') which fixes an obscure issue with mremap()'s
pagetable handling during a subsequent exec(), based upon an
implementation which Linus suggested
- More DAMON/DAMOS maintenance and feature work from SeongJae Park i
the following patch series:
mm/damon: misc fixups for documents, comments and its tracepoint
mm/damon: add a tracepoint for damos apply target regions
mm/damon: provide pseudo-moving sum based access rate
mm/damon: implement DAMOS apply intervals
mm/damon/core-test: Fix memory leaks in core-test
mm/damon/sysfs-schemes: Do DAMOS tried regions update for only one apply interval
- In the series 'Do not try to access unaccepted memory' Adrian
Hunter provides some fixups for the recently-added 'unaccepted
memory' feature. To increase the feature's checking coverage. 'Plug
a few gaps where RAM is exposed without checking if it is
unaccepted memory'
- In the series 'cleanups for lockless slab shrink' Qi Zheng has done
some maintenance work which is preparation for the lockless slab
shrinking code
- Qi Zheng has redone the earlier (and reverted) attempt to make slab
shrinking lockless in the series 'use refcount+RCU method to
implement lockless slab shrink'
- David Hildenbrand contributes some maintenance work for the rmap
code in the series 'Anon rmap cleanups'
- Kefeng Wang does more folio conversions and some maintenance work
in the migration code. Series 'mm: migrate: more folio conversion
and unification'
- Matthew Wilcox has fixed an issue in the buffer_head code which was
causing long stalls under some heavy memory/IO loads. Some cleanups
were added on the way. Series 'Add and use bdev_getblk()'
- In the series 'Use nth_page() in place of direct struct page
manipulation' Zi Yan has fixed a potential issue with the direct
manipulation of hugetlb page frames
- In the series 'mm: hugetlb: Skip initialization of gigantic tail
struct pages if freed by HVO' has improved our handling of gigantic
pages in the hugetlb vmmemmep optimizaton code. This provides
significant boot time improvements when significant amounts of
gigantic pages are in use
- Matthew Wilcox has sent the series 'Small hugetlb cleanups' - code
rationalization and folio conversions in the hugetlb code
- Yin Fengwei has improved mlock()'s handling of large folios in the
series 'support large folio for mlock'
- In the series 'Expose swapcache stat for memcg v1' Liu Shixin has
added statistics for memcg v1 users which are available (and
useful) under memcg v2
- Florent Revest has enhanced the MDWE (Memory-Deny-Write-Executable)
prctl so that userspace may direct the kernel to not automatically
propagate the denial to child processes. The series is named 'MDWE
without inheritance'
- Kefeng Wang has provided the series 'mm: convert numa balancing
functions to use a folio' which does what it says
- In the series 'mm/ksm: add fork-exec support for prctl' Stefan
Roesch makes is possible for a process to propagate KSM treatment
across exec()
- Huang Ying has enhanced memory tiering's calculation of memory
distances. This is used to permit the dax/kmem driver to use 'high
bandwidth memory' in addition to Optane Data Center Persistent
Memory Modules (DCPMM). The series is named 'memory tiering:
calculate abstract distance based on ACPI HMAT'
- In the series 'Smart scanning mode for KSM' Stefan Roesch has
optimized KSM by teaching it to retain and use some historical
information from previous scans
- Yosry Ahmed has fixed some inconsistencies in memcg statistics in
the series 'mm: memcg: fix tracking of pending stats updates
values'
- In the series 'Implement IOCTL to get and optionally clear info
about PTEs' Peter Xu has added an ioctl to /proc/<pid>/pagemap
which permits us to atomically read-then-clear page softdirty
state. This is mainly used by CRIU
- Hugh Dickins contributed the series 'shmem,tmpfs: general
maintenance', a bunch of relatively minor maintenance tweaks to
this code
- Matthew Wilcox has increased the use of the VMA lock over
file-backed page faults in the series 'Handle more faults under the
VMA lock'. Some rationalizations of the fault path became possible
as a result
- In the series 'mm/rmap: convert page_move_anon_rmap() to
folio_move_anon_rmap()' David Hildenbrand has implemented some
cleanups and folio conversions
- In the series 'various improvements to the GUP interface' Lorenzo
Stoakes has simplified and improved the GUP interface with an eye
to providing groundwork for future improvements
- Andrey Konovalov has sent along the series 'kasan: assorted fixes
and improvements' which does those things
- Some page allocator maintenance work from Kemeng Shi in the series
'Two minor cleanups to break_down_buddy_pages'
- In thes series 'New selftest for mm' Breno Leitao has developed
another MM self test which tickles a race we had between madvise()
and page faults
- In the series 'Add folio_end_read' Matthew Wilcox provides cleanups
and an optimization to the core pagecache code
- Nhat Pham has added memcg accounting for hugetlb memory in the
series 'hugetlb memcg accounting'
- Cleanups and rationalizations to the pagemap code from Lorenzo
Stoakes, in the series 'Abstract vma_merge() and split_vma()'
- Audra Mitchell has fixed issues in the procfs page_owner code's new
timestamping feature which was causing some misbehaviours. In the
series 'Fix page_owner's use of free timestamps'
- Lorenzo Stoakes has fixed the handling of new mappings of sealed
files in the series 'permit write-sealed memfd read-only shared
mappings'
- Mike Kravetz has optimized the hugetlb vmemmap optimization in the
series 'Batch hugetlb vmemmap modification operations'
- Some buffer_head folio conversions and cleanups from Matthew Wilcox
in the series 'Finish the create_empty_buffers() transition'
- As a page allocator performance optimization Huang Ying has added
automatic tuning to the allocator's per-cpu-pages feature, in the
series 'mm: PCP high auto-tuning'
- Roman Gushchin has contributed the patchset 'mm: improve
performance of accounted kernel memory allocations' which improves
their performance by ~30% as measured by a micro-benchmark
- folio conversions from Kefeng Wang in the series 'mm: convert page
cpupid functions to folios'
- Some kmemleak fixups in Liu Shixin's series 'Some bugfix about
kmemleak'
- Qi Zheng has improved our handling of memoryless nodes by keeping
them off the allocation fallback list. This is done in the series
'handle memoryless nodes more appropriately'
- khugepaged conversions from Vishal Moola in the series 'Some
khugepaged folio conversions'"
[ bcachefs conflicts with the dynamically allocated shrinkers have been
resolved as per Stephen Rothwell in
https://lore.kernel.org/all/20230913093553.4290421e@canb.auug.org.au/
with help from Qi Zheng.
The clone3 test filtering conflict was half-arsed by yours truly ]
* tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (406 commits)
mm/damon/sysfs: update monitoring target regions for online input commit
mm/damon/sysfs: remove requested targets when online-commit inputs
selftests: add a sanity check for zswap
Documentation: maple_tree: fix word spelling error
mm/vmalloc: fix the unchecked dereference warning in vread_iter()
zswap: export compression failure stats
Documentation: ubsan: drop "the" from article title
mempolicy: migration attempt to match interleave nodes
mempolicy: mmap_lock is not needed while migrating folios
mempolicy: alloc_pages_mpol() for NUMA policy without vma
mm: add page_rmappable_folio() wrapper
mempolicy: remove confusing MPOL_MF_LAZY dead code
mempolicy: mpol_shared_policy_init() without pseudo-vma
mempolicy trivia: use pgoff_t in shared mempolicy tree
mempolicy trivia: slightly more consistent naming
mempolicy trivia: delete those ancient pr_debug()s
mempolicy: fix migrate_pages(2) syscall return nr_failed
kernfs: drop shared NUMA mempolicy hooks
hugetlbfs: drop shared NUMA mempolicy pretence
mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets()
...
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r-- | mm/vmscan.c | 734 |
1 files changed, 22 insertions, 712 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 6f13394b112e..506f8220c5fe 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -35,7 +35,6 @@ #include <linux/cpuset.h> #include <linux/compaction.h> #include <linux/notifier.h> -#include <linux/rwsem.h> #include <linux/delay.h> #include <linux/kthread.h> #include <linux/freezer.h> @@ -188,246 +187,7 @@ struct scan_control { */ int vm_swappiness = 60; -LIST_HEAD(shrinker_list); -DECLARE_RWSEM(shrinker_rwsem); - #ifdef CONFIG_MEMCG -static int shrinker_nr_max; - -/* The shrinker_info is expanded in a batch of BITS_PER_LONG */ -static inline int shrinker_map_size(int nr_items) -{ - return (DIV_ROUND_UP(nr_items, BITS_PER_LONG) * sizeof(unsigned long)); -} - -static inline int shrinker_defer_size(int nr_items) -{ - return (round_up(nr_items, BITS_PER_LONG) * sizeof(atomic_long_t)); -} - -static struct shrinker_info *shrinker_info_protected(struct mem_cgroup *memcg, - int nid) -{ - return rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info, - lockdep_is_held(&shrinker_rwsem)); -} - -static int expand_one_shrinker_info(struct mem_cgroup *memcg, - int map_size, int defer_size, - int old_map_size, int old_defer_size, - int new_nr_max) -{ - struct shrinker_info *new, *old; - struct mem_cgroup_per_node *pn; - int nid; - int size = map_size + defer_size; - - for_each_node(nid) { - pn = memcg->nodeinfo[nid]; - old = shrinker_info_protected(memcg, nid); - /* Not yet online memcg */ - if (!old) - return 0; - - /* Already expanded this shrinker_info */ - if (new_nr_max <= old->map_nr_max) - continue; - - new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, nid); - if (!new) - return -ENOMEM; - - new->nr_deferred = (atomic_long_t *)(new + 1); - new->map = (void *)new->nr_deferred + defer_size; - new->map_nr_max = new_nr_max; - - /* map: set all old bits, clear all new bits */ - memset(new->map, (int)0xff, old_map_size); - memset((void *)new->map + old_map_size, 0, map_size - old_map_size); - /* nr_deferred: copy old values, clear all new values */ - memcpy(new->nr_deferred, old->nr_deferred, old_defer_size); - memset((void *)new->nr_deferred + old_defer_size, 0, - defer_size - old_defer_size); - - rcu_assign_pointer(pn->shrinker_info, new); - kvfree_rcu(old, rcu); - } - - return 0; -} - -void free_shrinker_info(struct mem_cgroup *memcg) -{ - struct mem_cgroup_per_node *pn; - struct shrinker_info *info; - int nid; - - for_each_node(nid) { - pn = memcg->nodeinfo[nid]; - info = rcu_dereference_protected(pn->shrinker_info, true); - kvfree(info); - rcu_assign_pointer(pn->shrinker_info, NULL); - } -} - -int alloc_shrinker_info(struct mem_cgroup *memcg) -{ - struct shrinker_info *info; - int nid, size, ret = 0; - int map_size, defer_size = 0; - - down_write(&shrinker_rwsem); - map_size = shrinker_map_size(shrinker_nr_max); - defer_size = shrinker_defer_size(shrinker_nr_max); - size = map_size + defer_size; - for_each_node(nid) { - info = kvzalloc_node(sizeof(*info) + size, GFP_KERNEL, nid); - if (!info) { - free_shrinker_info(memcg); - ret = -ENOMEM; - break; - } - info->nr_deferred = (atomic_long_t *)(info + 1); - info->map = (void *)info->nr_deferred + defer_size; - info->map_nr_max = shrinker_nr_max; - rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info); - } - up_write(&shrinker_rwsem); - - return ret; -} - -static int expand_shrinker_info(int new_id) -{ - int ret = 0; - int new_nr_max = round_up(new_id + 1, BITS_PER_LONG); - int map_size, defer_size = 0; - int old_map_size, old_defer_size = 0; - struct mem_cgroup *memcg; - - if (!root_mem_cgroup) - goto out; - - lockdep_assert_held(&shrinker_rwsem); - - map_size = shrinker_map_size(new_nr_max); - defer_size = shrinker_defer_size(new_nr_max); - old_map_size = shrinker_map_size(shrinker_nr_max); - old_defer_size = shrinker_defer_size(shrinker_nr_max); - - memcg = mem_cgroup_iter(NULL, NULL, NULL); - do { - ret = expand_one_shrinker_info(memcg, map_size, defer_size, - old_map_size, old_defer_size, - new_nr_max); - if (ret) { - mem_cgroup_iter_break(NULL, memcg); - goto out; - } - } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL); -out: - if (!ret) - shrinker_nr_max = new_nr_max; - - return ret; -} - -void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) -{ - if (shrinker_id >= 0 && memcg && !mem_cgroup_is_root(memcg)) { - struct shrinker_info *info; - - rcu_read_lock(); - info = rcu_dereference(memcg->nodeinfo[nid]->shrinker_info); - if (!WARN_ON_ONCE(shrinker_id >= info->map_nr_max)) { - /* Pairs with smp mb in shrink_slab() */ - smp_mb__before_atomic(); - set_bit(shrinker_id, info->map); - } - rcu_read_unlock(); - } -} - -static DEFINE_IDR(shrinker_idr); - -static int prealloc_memcg_shrinker(struct shrinker *shrinker) -{ - int id, ret = -ENOMEM; - - if (mem_cgroup_disabled()) - return -ENOSYS; - - down_write(&shrinker_rwsem); - /* This may call shrinker, so it must use down_read_trylock() */ - id = idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL); - if (id < 0) - goto unlock; - - if (id >= shrinker_nr_max) { - if (expand_shrinker_info(id)) { - idr_remove(&shrinker_idr, id); - goto unlock; - } - } - shrinker->id = id; - ret = 0; -unlock: - up_write(&shrinker_rwsem); - return ret; -} - -static void unregister_memcg_shrinker(struct shrinker *shrinker) -{ - int id = shrinker->id; - - BUG_ON(id < 0); - - lockdep_assert_held(&shrinker_rwsem); - - idr_remove(&shrinker_idr, id); -} - -static long xchg_nr_deferred_memcg(int nid, struct shrinker *shrinker, - struct mem_cgroup *memcg) -{ - struct shrinker_info *info; - - info = shrinker_info_protected(memcg, nid); - return atomic_long_xchg(&info->nr_deferred[shrinker->id], 0); -} - -static long add_nr_deferred_memcg(long nr, int nid, struct shrinker *shrinker, - struct mem_cgroup *memcg) -{ - struct shrinker_info *info; - - info = shrinker_info_protected(memcg, nid); - return atomic_long_add_return(nr, &info->nr_deferred[shrinker->id]); -} - -void reparent_shrinker_deferred(struct mem_cgroup *memcg) -{ - int i, nid; - long nr; - struct mem_cgroup *parent; - struct shrinker_info *child_info, *parent_info; - - parent = parent_mem_cgroup(memcg); - if (!parent) - parent = root_mem_cgroup; - - /* Prevent from concurrent shrinker_info expand */ - down_read(&shrinker_rwsem); - for_each_node(nid) { - child_info = shrinker_info_protected(memcg, nid); - parent_info = shrinker_info_protected(parent, nid); - for (i = 0; i < child_info->map_nr_max; i++) { - nr = atomic_long_read(&child_info->nr_deferred[i]); - atomic_long_add(nr, &parent_info->nr_deferred[i]); - } - } - up_read(&shrinker_rwsem); -} /* Returns true for reclaim through cgroup limits or cgroup interfaces. */ static bool cgroup_reclaim(struct scan_control *sc) @@ -468,27 +228,6 @@ static bool writeback_throttling_sane(struct scan_control *sc) return false; } #else -static int prealloc_memcg_shrinker(struct shrinker *shrinker) -{ - return -ENOSYS; -} - -static void unregister_memcg_shrinker(struct shrinker *shrinker) -{ -} - -static long xchg_nr_deferred_memcg(int nid, struct shrinker *shrinker, - struct mem_cgroup *memcg) -{ - return 0; -} - -static long add_nr_deferred_memcg(long nr, int nid, struct shrinker *shrinker, - struct mem_cgroup *memcg) -{ - return 0; -} - static bool cgroup_reclaim(struct scan_control *sc) { return false; @@ -557,39 +296,6 @@ static void flush_reclaim_state(struct scan_control *sc) } } -static long xchg_nr_deferred(struct shrinker *shrinker, - struct shrink_control *sc) -{ - int nid = sc->nid; - - if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) - nid = 0; - - if (sc->memcg && - (shrinker->flags & SHRINKER_MEMCG_AWARE)) - return xchg_nr_deferred_memcg(nid, shrinker, - sc->memcg); - - return atomic_long_xchg(&shrinker->nr_deferred[nid], 0); -} - - -static long add_nr_deferred(long nr, struct shrinker *shrinker, - struct shrink_control *sc) -{ - int nid = sc->nid; - - if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) - nid = 0; - - if (sc->memcg && - (shrinker->flags & SHRINKER_MEMCG_AWARE)) - return add_nr_deferred_memcg(nr, nid, shrinker, - sc->memcg); - - return atomic_long_add_return(nr, &shrinker->nr_deferred[nid]); -} - static bool can_demote(int nid, struct scan_control *sc) { if (!numa_demotion_enabled) @@ -671,413 +377,6 @@ static unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, return size; } -/* - * Add a shrinker callback to be called from the vm. - */ -static int __prealloc_shrinker(struct shrinker *shrinker) -{ - unsigned int size; - int err; - - if (shrinker->flags & SHRINKER_MEMCG_AWARE) { - err = prealloc_memcg_shrinker(shrinker); - if (err != -ENOSYS) - return err; - - shrinker->flags &= ~SHRINKER_MEMCG_AWARE; - } - - size = sizeof(*shrinker->nr_deferred); - if (shrinker->flags & SHRINKER_NUMA_AWARE) - size *= nr_node_ids; - - shrinker->nr_deferred = kzalloc(size, GFP_KERNEL); - if (!shrinker->nr_deferred) - return -ENOMEM; - - return 0; -} - -#ifdef CONFIG_SHRINKER_DEBUG -int prealloc_shrinker(struct shrinker *shrinker, const char *fmt, ...) -{ - va_list ap; - int err; - - va_start(ap, fmt); - shrinker->name = kvasprintf_const(GFP_KERNEL, fmt, ap); - va_end(ap); - if (!shrinker->name) - return -ENOMEM; - - err = __prealloc_shrinker(shrinker); - if (err) { - kfree_const(shrinker->name); - shrinker->name = NULL; - } - - return err; -} -#else -int prealloc_shrinker(struct shrinker *shrinker, const char *fmt, ...) -{ - return __prealloc_shrinker(shrinker); -} -#endif - -void free_prealloced_shrinker(struct shrinker *shrinker) -{ -#ifdef CONFIG_SHRINKER_DEBUG - kfree_const(shrinker->name); - shrinker->name = NULL; -#endif - if (shrinker->flags & SHRINKER_MEMCG_AWARE) { - down_write(&shrinker_rwsem); - unregister_memcg_shrinker(shrinker); - up_write(&shrinker_rwsem); - return; - } - - kfree(shrinker->nr_deferred); - shrinker->nr_deferred = NULL; -} - -void register_shrinker_prepared(struct shrinker *shrinker) -{ - down_write(&shrinker_rwsem); - list_add_tail(&shrinker->list, &shrinker_list); - shrinker->flags |= SHRINKER_REGISTERED; - shrinker_debugfs_add(shrinker); - up_write(&shrinker_rwsem); -} - -static int __register_shrinker(struct shrinker *shrinker) -{ - int err = __prealloc_shrinker(shrinker); - - if (err) - return err; - register_shrinker_prepared(shrinker); - return 0; -} - -#ifdef CONFIG_SHRINKER_DEBUG -int register_shrinker(struct shrinker *shrinker, const char *fmt, ...) -{ - va_list ap; - int err; - - va_start(ap, fmt); - shrinker->name = kvasprintf_const(GFP_KERNEL, fmt, ap); - va_end(ap); - if (!shrinker->name) - return -ENOMEM; - - err = __register_shrinker(shrinker); - if (err) { - kfree_const(shrinker->name); - shrinker->name = NULL; - } - return err; -} -#else -int register_shrinker(struct shrinker *shrinker, const char *fmt, ...) -{ - return __register_shrinker(shrinker); -} -#endif -EXPORT_SYMBOL(register_shrinker); - -/* - * Remove one - */ -void unregister_shrinker(struct shrinker *shrinker) -{ - struct dentry *debugfs_entry; - int debugfs_id; - - if (!(shrinker->flags & SHRINKER_REGISTERED)) - return; - - down_write(&shrinker_rwsem); - list_del(&shrinker->list); - shrinker->flags &= ~SHRINKER_REGISTERED; - if (shrinker->flags & SHRINKER_MEMCG_AWARE) - unregister_memcg_shrinker(shrinker); - debugfs_entry = shrinker_debugfs_detach(shrinker, &debugfs_id); - up_write(&shrinker_rwsem); - - shrinker_debugfs_remove(debugfs_entry, debugfs_id); - - kfree(shrinker->nr_deferred); - shrinker->nr_deferred = NULL; -} -EXPORT_SYMBOL(unregister_shrinker); - -/** - * synchronize_shrinkers - Wait for all running shrinkers to complete. - * - * This is equivalent to calling unregister_shrink() and register_shrinker(), - * but atomically and with less overhead. This is useful to guarantee that all - * shrinker invocations have seen an update, before freeing memory, similar to - * rcu. - */ -void synchronize_shrinkers(void) -{ - down_write(&shrinker_rwsem); - up_write(&shrinker_rwsem); -} -EXPORT_SYMBOL(synchronize_shrinkers); - -#define SHRINK_BATCH 128 - -static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, - struct shrinker *shrinker, int priority) -{ - unsigned long freed = 0; - unsigned long long delta; - long total_scan; - long freeable; - long nr; - long new_nr; - long batch_size = shrinker->batch ? shrinker->batch - : SHRINK_BATCH; - long scanned = 0, next_deferred; - - freeable = shrinker->count_objects(shrinker, shrinkctl); - if (freeable == 0 || freeable == SHRINK_EMPTY) - return freeable; - - /* - * copy the current shrinker scan count into a local variable - * and zero it so that other concurrent shrinker invocations - * don't also do this scanning work. - */ - nr = xchg_nr_deferred(shrinker, shrinkctl); - - if (shrinker->seeks) { - delta = freeable >> priority; - delta *= 4; - do_div(delta, shrinker->seeks); - } else { - /* - * These objects don't require any IO to create. Trim - * them aggressively under memory pressure to keep - * them from causing refetches in the IO caches. - */ - delta = freeable / 2; - } - - total_scan = nr >> priority; - total_scan += delta; - total_scan = min(total_scan, (2 * freeable)); - - trace_mm_shrink_slab_start(shrinker, shrinkctl, nr, - freeable, delta, total_scan, priority); - - /* - * Normally, we should not scan less than batch_size objects in one - * pass to avoid too frequent shrinker calls, but if the slab has less - * than batch_size objects in total and we are really tight on memory, - * we will try to reclaim all available objects, otherwise we can end - * up failing allocations although there are plenty of reclaimable - * objects spread over several slabs with usage less than the - * batch_size. - * - * We detect the "tight on memory" situations by looking at the total - * number of objects we want to scan (total_scan). If it is greater - * than the total number of objects on slab (freeable), we must be - * scanning at high prio and therefore should try to reclaim as much as - * possible. - */ - while (total_scan >= batch_size || - total_scan >= freeable) { - unsigned long ret; - unsigned long nr_to_scan = min(batch_size, total_scan); - - shrinkctl->nr_to_scan = nr_to_scan; - shrinkctl->nr_scanned = nr_to_scan; - ret = shrinker->scan_objects(shrinker, shrinkctl); - if (ret == SHRINK_STOP) - break; - freed += ret; - - count_vm_events(SLABS_SCANNED, shrinkctl->nr_scanned); - total_scan -= shrinkctl->nr_scanned; - scanned += shrinkctl->nr_scanned; - - cond_resched(); - } - - /* - * The deferred work is increased by any new work (delta) that wasn't - * done, decreased by old deferred work that was done now. - * - * And it is capped to two times of the freeable items. - */ - next_deferred = max_t(long, (nr + delta - scanned), 0); - next_deferred = min(next_deferred, (2 * freeable)); - - /* - * move the unused scan count back into the shrinker in a - * manner that handles concurrent updates. - */ - new_nr = add_nr_deferred(next_deferred, shrinker, shrinkctl); - - trace_mm_shrink_slab_end(shrinker, shrinkctl->nid, freed, nr, new_nr, total_scan); - return freed; -} - -#ifdef CONFIG_MEMCG -static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid, - struct mem_cgroup *memcg, int priority) -{ - struct shrinker_info *info; - unsigned long ret, freed = 0; - int i; - - if (!mem_cgroup_online(memcg)) - return 0; - - if (!down_read_trylock(&shrinker_rwsem)) - return 0; - - info = shrinker_info_protected(memcg, nid); - if (unlikely(!info)) - goto unlock; - - for_each_set_bit(i, info->map, info->map_nr_max) { - struct shrink_control sc = { - .gfp_mask = gfp_mask, - .nid = nid, - .memcg = memcg, - }; - struct shrinker *shrinker; - - shrinker = idr_find(&shrinker_idr, i); - if (unlikely(!shrinker || !(shrinker->flags & SHRINKER_REGISTERED))) { - if (!shrinker) - clear_bit(i, info->map); - continue; - } - - /* Call non-slab shrinkers even though kmem is disabled */ - if (!memcg_kmem_online() && - !(shrinker->flags & SHRINKER_NONSLAB)) - continue; - - ret = do_shrink_slab(&sc, shrinker, priority); - if (ret == SHRINK_EMPTY) { - clear_bit(i, info->map); - /* - * After the shrinker reported that it had no objects to - * free, but before we cleared the corresponding bit in - * the memcg shrinker map, a new object might have been - * added. To make sure, we have the bit set in this - * case, we invoke the shrinker one more time and reset - * the bit if it reports that it is not empty anymore. - * The memory barrier here pairs with the barrier in - * set_shrinker_bit(): - * - * list_lru_add() shrink_slab_memcg() - * list_add_tail() clear_bit() - * <MB> <MB> - * set_bit() do_shrink_slab() - */ - smp_mb__after_atomic(); - ret = do_shrink_slab(&sc, shrinker, priority); - if (ret == SHRINK_EMPTY) - ret = 0; - else - set_shrinker_bit(memcg, nid, i); - } - freed += ret; - - if (rwsem_is_contended(&shrinker_rwsem)) { - freed = freed ? : 1; - break; - } - } -unlock: - up_read(&shrinker_rwsem); - return freed; -} -#else /* CONFIG_MEMCG */ -static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid, - struct mem_cgroup *memcg, int priority) -{ - return 0; -} -#endif /* CONFIG_MEMCG */ - -/** - * shrink_slab - shrink slab caches - * @gfp_mask: allocation context - * @nid: node whose slab caches to target - * @memcg: memory cgroup whose slab caches to target - * @priority: the reclaim priority - * - * Call the shrink functions to age shrinkable caches. - * - * @nid is passed along to shrinkers with SHRINKER_NUMA_AWARE set, - * unaware shrinkers will receive a node id of 0 instead. - * - * @memcg specifies the memory cgroup to target. Unaware shrinkers - * are called only if it is the root cgroup. - * - * @priority is sc->priority, we take the number of objects and >> by priority - * in order to get the scan target. - * - * Returns the number of reclaimed slab objects. - */ -static unsigned long shrink_slab(gfp_t gfp_mask, int nid, - struct mem_cgroup *memcg, - int priority) -{ - unsigned long ret, freed = 0; - struct shrinker *shrinker; - - /* - * The root memcg might be allocated even though memcg is disabled - * via "cgroup_disable=memory" boot parameter. This could make - * mem_cgroup_is_root() return false, then just run memcg slab - * shrink, but skip global shrink. This may result in premature - * oom. - */ - if (!mem_cgroup_disabled() && !mem_cgroup_is_root(memcg)) - return shrink_slab_memcg(gfp_mask, nid, memcg, priority); - - if (!down_read_trylock(&shrinker_rwsem)) - goto out; - - list_for_each_entry(shrinker, &shrinker_list, list) { - struct shrink_control sc = { - .gfp_mask = gfp_mask, - .nid = nid, - .memcg = memcg, - }; - - ret = do_shrink_slab(&sc, shrinker, priority); - if (ret == SHRINK_EMPTY) - ret = 0; - freed += ret; - /* - * Bail out if someone want to register a new shrinker to - * prevent the registration from being stalled for long periods - * by parallel ongoing shrinking. - */ - if (rwsem_is_contended(&shrinker_rwsem)) { - freed = freed ? : 1; - break; - } - } - - up_read(&shrinker_rwsem); -out: - cond_resched(); - return freed; -} - static unsigned long drop_slab_node(int nid) { unsigned long freed = 0; @@ -1915,6 +1214,7 @@ retry: folio_list)) goto activate_locked; #ifdef CONFIG_TRANSPARENT_HUGEPAGE + count_memcg_folio_events(folio, THP_SWPOUT_FALLBACK, 1); count_vm_event(THP_SWPOUT_FALLBACK); #endif if (!add_to_swap(folio)) @@ -2271,7 +1571,7 @@ static bool skip_cma(struct folio *folio, struct scan_control *sc) { return !current_is_kswapd() && gfp_migratetype(sc->gfp_mask) != MIGRATE_MOVABLE && - get_pageblock_migratetype(&folio->page) == MIGRATE_CMA; + folio_migratetype(folio) == MIGRATE_CMA; } #else static bool skip_cma(struct folio *folio, struct scan_control *sc) @@ -2389,8 +1689,7 @@ move: } *nr_scanned = total_scan; trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan, - total_scan, skipped, nr_taken, - sc->may_unmap ? 0 : ISOLATE_UNMAPPED, lru); + total_scan, skipped, nr_taken, lru); update_lru_sizes(lruvec, lru, nr_zone_taken); return nr_taken; } @@ -2909,7 +2208,7 @@ enum scan_balance { SCAN_FILE, }; -static void prepare_scan_count(pg_data_t *pgdat, struct scan_control *sc) +static void prepare_scan_control(pg_data_t *pgdat, struct scan_control *sc) { unsigned long file; struct lruvec *target_lruvec; @@ -5005,6 +4304,7 @@ static int scan_folios(struct lruvec *lruvec, struct scan_control *sc, int sorted = 0; int scanned = 0; int isolated = 0; + int skipped = 0; int remaining = MAX_LRU_BATCH; struct lru_gen_folio *lrugen = &lruvec->lrugen; struct mem_cgroup *memcg = lruvec_memcg(lruvec); @@ -5018,7 +4318,7 @@ static int scan_folios(struct lruvec *lruvec, struct scan_control *sc, for (i = MAX_NR_ZONES; i > 0; i--) { LIST_HEAD(moved); - int skipped = 0; + int skipped_zone = 0; int zone = (sc->reclaim_idx + i) % MAX_NR_ZONES; struct list_head *head = &lrugen->folios[gen][type][zone]; @@ -5040,16 +4340,17 @@ static int scan_folios(struct lruvec *lruvec, struct scan_control *sc, isolated += delta; } else { list_move(&folio->lru, &moved); - skipped += delta; + skipped_zone += delta; } - if (!--remaining || max(isolated, skipped) >= MIN_LRU_BATCH) + if (!--remaining || max(isolated, skipped_zone) >= MIN_LRU_BATCH) break; } - if (skipped) { + if (skipped_zone) { list_splice(&moved, head); - __count_zid_vm_events(PGSCAN_SKIP, zone, skipped); + __count_zid_vm_events(PGSCAN_SKIP, zone, skipped_zone); + skipped += skipped_zone; } if (!remaining || isolated >= MIN_LRU_BATCH) @@ -5064,6 +4365,9 @@ static int scan_folios(struct lruvec *lruvec, struct scan_control *sc, __count_memcg_events(memcg, item, isolated); __count_memcg_events(memcg, PGREFILL, sorted); __count_vm_events(PGSCAN_ANON + type, isolated); + trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, MAX_LRU_BATCH, + scanned, skipped, isolated, + type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON); /* * There might not be eligible folios due to reclaim_idx. Check the @@ -5194,6 +4498,9 @@ static int evict_folios(struct lruvec *lruvec, struct scan_control *sc, int swap retry: reclaimed = shrink_folio_list(&list, pgdat, sc, &stat, false); sc->nr_reclaimed += reclaimed; + trace_mm_vmscan_lru_shrink_inactive(pgdat->node_id, + scanned, reclaimed, &stat, sc->priority, + type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON); list_for_each_entry_safe_reverse(folio, next, &list, lru) { if (!folio_evictable(folio)) { @@ -6535,7 +5842,7 @@ again: nr_reclaimed = sc->nr_reclaimed; nr_scanned = sc->nr_scanned; - prepare_scan_count(pgdat, sc); + prepare_scan_control(pgdat, sc); shrink_node_memcgs(pgdat, sc); @@ -7892,8 +7199,9 @@ void __meminit kswapd_run(int nid) pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid); if (IS_ERR(pgdat->kswapd)) { /* failure at boot is fatal */ + pr_err("Failed to start kswapd on node %d,ret=%ld\n", + nid, PTR_ERR(pgdat->kswapd)); BUG_ON(system_state < SYSTEM_RUNNING); - pr_err("Failed to start kswapd on node %d\n", nid); pgdat->kswapd = NULL; } } @@ -8026,6 +7334,7 @@ static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in cond_resched(); psi_memstall_enter(&pflags); + delayacct_freepages_start(); fs_reclaim_acquire(sc.gfp_mask); /* * We need to be able to allocate from the reserves for RECLAIM_UNMAP @@ -8048,6 +7357,7 @@ static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in memalloc_noreclaim_restore(noreclaim_flag); fs_reclaim_release(sc.gfp_mask); psi_memstall_leave(&pflags); + delayacct_freepages_end(); trace_mm_vmscan_node_reclaim_end(sc.nr_reclaimed); |