Hi, Kmem accounting of memcg is unusable now, because it lacks slab shrinker support. That means when we hit the limit we will get ENOMEM w/o any chance to recover. What we should do then is to call shrink_slab, which would reclaim old inode/dentry caches from this cgroup. This is what this patch set is intended to do. Basically, it does two things. First, it introduces the notion of per-memcg slab shrinker. A shrinker that wants to reclaim objects per cgroup should mark itself as SHRINKER_MEMCG_AWARE. Then it will be passed the memory cgroup to scan from in shrink_control->memcg. For such shrinkers shrink_slab iterates over the whole cgroup subtree under the target cgroup and calls the shrinker for each kmem-active memory cgroup. Secondly, this patch set makes the list_lru structure per-memcg. It's done transparently to list_lru users - everything they have to do is to tell list_lru_init that they want memcg-aware list_lru. Then the list_lru will automatically distribute objects among per-memcg lists basing on which cgroup the object is accounted to. This way to make FS shrinkers (icache, dcache) memcg-aware we only need to make them use memcg-aware list_lru, and this is what this patch set does. As before, this patch set only enables per-memcg kmem reclaim when the pressure goes from memory.limit, not from memory.kmem.limit. Handling memory.kmem.limit is going to be tricky due to GFP_NOFS allocations, and it is still unclear whether we will have this knob in the unified hierarchy. Changes in v3: - Removed extra walk over all memory cgroups for shrinking per memcg slab caches; shrink_slab is now called per memcg from the loop in shrink_zone, as suggested by Johannes - Reworked list_lru per memcg arrays init/destroy/update functions, hopefully making them more readable - Rebased on top of v3.19-rc3-mmotm-2015-01-07-17-07 v2: https://lkml.org/lkml/2014/10/24/219 v1: https://lkml.org/lkml/2014/9/21/64 The patch set is organized as follows: - Patches 1-3 implement per-memcg shrinker core with patches 1 and 2 preparing list_lru users for upcoming changes and patch 3 tuning shrink_slab. - Patches 4 and 5 cleanup handling of max memcg_cache_id in the memcg core. - Patch 6 gets rid of the useless list_lru->active_nodes, and patch 7 links all list_lrus to a list, which is required by memcg. - Patch 8 adds per-memcg lrus to the list_lru structure, and finally patch 9 marks fs shrinkers as memcg aware. Thanks, Vladimir Davydov (9): list_lru: introduce list_lru_shrink_{count,walk} fs: consolidate {nr,free}_cached_objects args in shrink_control vmscan: per memory cgroup slab shrinkers memcg: rename some cache id related variables memcg: add rwsem to synchronize against memcg_caches arrays relocation list_lru: get rid of ->active_nodes list_lru: organize all list_lrus to list list_lru: introduce per-memcg lists fs: make shrinker memcg aware fs/dcache.c | 14 +- fs/drop_caches.c | 14 -- fs/gfs2/quota.c | 6 +- fs/inode.c | 7 +- fs/internal.h | 7 +- fs/super.c | 44 +++-- fs/xfs/xfs_buf.c | 7 +- fs/xfs/xfs_qm.c | 7 +- fs/xfs/xfs_super.c | 7 +- include/linux/fs.h | 6 +- include/linux/list_lru.h | 70 ++++++-- include/linux/memcontrol.h | 37 +++- include/linux/mm.h | 5 +- include/linux/shrinker.h | 6 +- mm/list_lru.c | 412 +++++++++++++++++++++++++++++++++++++++++--- mm/memcontrol.c | 68 +++++--- mm/memory-failure.c | 11 +- mm/slab_common.c | 13 +- mm/vmscan.c | 86 ++++++--- mm/workingset.c | 6 +- 20 files changed, 657 insertions(+), 176 deletions(-) -- 1.7.10.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>