The patch titled Subject: fs: shrinker: always scan at least one object of each type has been added to the -mm tree. Its filename is fs-shrinker-always-scan-at-least-one-object-of-each-type.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/fs-shrinker-always-scan-at-least-one-object-of-each-type.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/fs-shrinker-always-scan-at-least-one-object-of-each-type.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Subject: fs: shrinker: always scan at least one object of each type In super_cache_scan() we divide the number of objects of particular type by the total number of objects in order to distribute pressure among As a result, in some corner cases we can get nr_to_scan=0 even if there are some objects to reclaim, e.g. dentries=1, inodes=1, fs_objects=1, nr_to_scan=1/3=0. This is unacceptable for per memcg kmem accounting, because this means that some objects may never get reclaimed after memcg death, preventing it from being freed. This patch therefore assures that super_cache_scan() will scan at least one object of each type if any. Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/super.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff -puN fs/super.c~fs-shrinker-always-scan-at-least-one-object-of-each-type fs/super.c --- a/fs/super.c~fs-shrinker-always-scan-at-least-one-object-of-each-type +++ a/fs/super.c @@ -92,13 +92,13 @@ static unsigned long super_cache_scan(st * prune the dcache first as the icache is pinned by it, then * prune the icache, followed by the filesystem specific caches */ - sc->nr_to_scan = dentries; + sc->nr_to_scan = dentries + 1; freed = prune_dcache_sb(sb, sc); - sc->nr_to_scan = inodes; + sc->nr_to_scan = inodes + 1; freed += prune_icache_sb(sb, sc); if (fs_objects) { - sc->nr_to_scan = fs_objects; + sc->nr_to_scan = fs_objects + 1; freed += sb->s_op->free_cached_objects(sb, sc); } _ Patches currently in -mm which might be from vdavydov@xxxxxxxxxxxxx are memcg-zap-__memcg_chargeuncharge_slab.patch memcg-zap-memcg_name-argument-of-memcg_create_kmem_cache.patch memcg-zap-memcg_slab_caches-and-memcg_slab_mutex.patch swap-remove-unused-mem_cgroup_uncharge_swapcache-declaration.patch mm-memcontrol-track-move_lock-state-internally.patch mm-vmscan-wake-up-all-pfmemalloc-throttled-processes-at-once.patch list_lru-introduce-list_lru_shrink_countwalk.patch fs-consolidate-nrfree_cached_objects-args-in-shrink_control.patch vmscan-per-memory-cgroup-slab-shrinkers.patch memcg-rename-some-cache-id-related-variables.patch memcg-add-rwsem-to-synchronize-against-memcg_caches-arrays-relocation.patch list_lru-get-rid-of-active_nodes.patch list_lru-organize-all-list_lrus-to-list.patch list_lru-introduce-per-memcg-lists.patch fs-make-shrinker-memcg-aware.patch vmscan-force-scan-offline-memory-cgroups.patch mm-page_counter-pull-1-handling-out-of-page_counter_memparse.patch mm-memcontrol-default-hierarchy-interface-for-memory.patch mm-memcontrol-remove-unnecessary-soft-limit-tree-node-test.patch mm-memcontrol-consolidate-memory-controller-initialization.patch mm-memcontrol-consolidate-swap-controller-code.patch fs-shrinker-always-scan-at-least-one-object-of-each-type.patch fs-shrinker-always-scan-at-least-one-object-of-each-type-fix.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html