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, it will probably require a sort of soft limit to work properly. I'm leaving this for future work. The main difference in v2 is that I got rid of reparenting of list_lrus. Thanks to Johannes' and Tejun's efforts mem_cgroup_iter now iterates over all memory cgroups including dead ones, so dangling offline cgroups whose css is pinned by kmem allocations is no longer a problem - they will be eventually reaped by memory pressure. OTOH, this allowed to simplify the patch set significantly. Nevertheless, if we want reparenting one day, it won't cause any problems to implement it on top. Another differences in v2 include: - Rebased on top of v3.18-rc1-mmotm-2014-10-23-16-26 - Simplified handling of the list of all list_lrus - Improved comments and function names - Fix leak on the list_lru_init error path - Fix list_lru_destroy crash on uninitialized zeroed object v1 can be found at 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. Reviews are more than welcome. Thanks, Vladimir Davydov (9): list_lru: introduce list_lru_shrink_{count,walk} fs: consolidate {nr,free}_cached_objects args in shrink_control vmscan: shrink slab on memcg pressure memcg: rename some cache id related variables memcg: add rwsem to sync 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/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 | 72 +++++++-- include/linux/memcontrol.h | 53 ++++++- include/linux/shrinker.h | 10 +- mm/list_lru.c | 361 ++++++++++++++++++++++++++++++++++++++++---- mm/memcontrol.c | 117 +++++++++++--- mm/slab_common.c | 14 +- mm/vmscan.c | 87 ++++++++--- mm/workingset.c | 6 +- 17 files changed, 678 insertions(+), 147 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>