From: Kirill Tkhai <ktk...@virtuozzo.com> Introduce shrinker::id number, which is used to enumerate memcg-aware shrinkers. The number start from 0, and the code tries to maintain it as small as possible.
This will be used to represent a memcg-aware shrinkers in memcg shrinkers map. Since all memcg-aware shrinkers are based on list_lru, which is per-memcg in case of !CONFIG_MEMCG_KMEM only, the new functionality will be under this config option. [ktk...@virtuozzo.com: v9] Link: http://lkml.kernel.org/r/153112546435.4097.10607140323811756557.stgit@localhost.localdomain Link: http://lkml.kernel.org/r/153063054586.1818.6041047871606697364.stgit@localhost.localdomain Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com> Acked-by: Vladimir Davydov <vdavydov....@gmail.com> Tested-by: Shakeel Butt <shake...@google.com> Cc: Al Viro <v...@zeniv.linux.org.uk> Cc: Andrey Ryabinin <aryabi...@virtuozzo.com> Cc: Chris Wilson <ch...@chris-wilson.co.uk> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> Cc: Guenter Roeck <li...@roeck-us.net> Cc: "Huang, Ying" <ying.hu...@intel.com> Cc: Johannes Weiner <han...@cmpxchg.org> Cc: Josef Bacik <jba...@fb.com> Cc: Li RongQing <lirongq...@baidu.com> Cc: Matthew Wilcox <wi...@infradead.org> Cc: Matthias Kaehlcke <m...@chromium.org> Cc: Mel Gorman <mgor...@techsingularity.net> Cc: Michal Hocko <mho...@kernel.org> Cc: Minchan Kim <minc...@kernel.org> Cc: Philippe Ombredanne <pombreda...@nexb.com> Cc: Roman Gushchin <g...@fb.com> Cc: Sahitya Tummala <stumm...@codeaurora.org> Cc: Stephen Rothwell <s...@canb.auug.org.au> Cc: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Waiman Long <long...@redhat.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> (cherry picked from commit b4c2b231c3ba155623591fb6301ed97b95e1c039) Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> --- include/linux/shrinker.h | 4 +++ mm/vmscan.c | 63 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 67 insertions(+) diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h index 8d912bc91bf5..cec7a37e8193 100644 --- a/include/linux/shrinker.h +++ b/include/linux/shrinker.h @@ -68,6 +68,10 @@ struct shrinker { /* These are for internal use */ struct list_head list; +#ifdef CONFIG_MEMCG_KMEM + /* ID in shrinker_idr */ + int id; +#endif /* objs pending delete, per node */ atomic_long_t *nr_deferred; }; diff --git a/mm/vmscan.c b/mm/vmscan.c index d99fb2be1c36..d14f954ab95b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -182,6 +182,50 @@ unsigned long vm_total_pages; static LIST_HEAD(shrinker_list); static DECLARE_RWSEM(shrinker_rwsem); +#ifdef CONFIG_MEMCG_KMEM +static DEFINE_IDR(shrinker_idr); +static int shrinker_nr_max; + +static int prealloc_memcg_shrinker(struct shrinker *shrinker) +{ + int id, ret = -ENOMEM; + + 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) + shrinker_nr_max = id + 1; + 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); + + down_write(&shrinker_rwsem); + idr_remove(&shrinker_idr, id); + up_write(&shrinker_rwsem); +} +#else /* CONFIG_MEMCG_KMEM */ +static int prealloc_memcg_shrinker(struct shrinker *shrinker) +{ + return 0; +} + +static void unregister_memcg_shrinker(struct shrinker *shrinker) +{ +} +#endif /* CONFIG_MEMCG_KMEM */ + #ifdef CONFIG_MEMCG static bool cgroup_reclaim(struct scan_control *sc) { @@ -281,11 +325,28 @@ int prealloc_shrinker(struct shrinker *shrinker) shrinker->nr_deferred = kzalloc(size, GFP_KERNEL); if (!shrinker->nr_deferred) return -ENOMEM; + + if (shrinker->flags & SHRINKER_MEMCG_AWARE) { + if (prealloc_memcg_shrinker(shrinker)) + goto free_deferred; + } + return 0; + +free_deferred: + kfree(shrinker->nr_deferred); + shrinker->nr_deferred = NULL; + return -ENOMEM; } void free_prealloced_shrinker(struct shrinker *shrinker) { + if (!shrinker->nr_deferred) + return; + + if (shrinker->flags & SHRINKER_MEMCG_AWARE) + unregister_memcg_shrinker(shrinker); + kfree(shrinker->nr_deferred); shrinker->nr_deferred = NULL; } @@ -315,6 +376,8 @@ void unregister_shrinker(struct shrinker *shrinker) { if (!shrinker->nr_deferred) return; + if (shrinker->flags & SHRINKER_MEMCG_AWARE) + unregister_memcg_shrinker(shrinker); down_write(&shrinker_rwsem); list_del(&shrinker->list); up_write(&shrinker_rwsem); -- 2.24.1 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
