From c9fc586403e7c85eee06b2d5dea14ce71c00fcd8 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 22 Feb 2017 15:41:27 -0800 Subject: [PATCH] slab: introduce __kmemcg_cache_deactivate() __kmem_cache_shrink() is called with %true @deactivate only for memcg caches. Remove @deactivate from __kmem_cache_shrink() and introduce __kmemcg_cache_deactivate() instead. Each memcg-supporting allocator should implement it and it should deactivate and drain the cache. This is to allow memcg cache deactivation behavior to further deviate from simple shrinking without messing up __kmem_cache_shrink(). This is pure reorganization and doesn't introduce any observable behavior changes. v2: Dropped unnecessary ifdef in mm/slab.h as suggested by Vladimir. Link: http://lkml.kernel.org/r/20170117235411.9408-8-tj@kernel.org Signed-off-by: Tejun Heo Acked-by: Vladimir Davydov Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 11 +++++++++-- mm/slab.h | 3 ++- mm/slab_common.c | 4 ++-- mm/slob.c | 2 +- mm/slub.c | 39 ++++++++++++++++++++++----------------- 5 files changed, 36 insertions(+), 23 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 8a0e3392f181..bd63450a9b16 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2315,7 +2315,7 @@ out: return nr_freed; } -int __kmem_cache_shrink(struct kmem_cache *cachep, bool deactivate) +int __kmem_cache_shrink(struct kmem_cache *cachep) { int ret = 0; int node; @@ -2333,9 +2333,16 @@ int __kmem_cache_shrink(struct kmem_cache *cachep, bool deactivate) return (ret ? 1 : 0); } +#ifdef CONFIG_MEMCG +void __kmemcg_cache_deactivate(struct kmem_cache *cachep) +{ + __kmem_cache_shrink(cachep); +} +#endif + int __kmem_cache_shutdown(struct kmem_cache *cachep) { - return __kmem_cache_shrink(cachep, false); + return __kmem_cache_shrink(cachep); } void __kmem_cache_release(struct kmem_cache *cachep) diff --git a/mm/slab.h b/mm/slab.h index 9631bb27c772..7bff1ee513c2 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -167,7 +167,8 @@ static inline unsigned long kmem_cache_flags(unsigned long object_size, int __kmem_cache_shutdown(struct kmem_cache *); void __kmem_cache_release(struct kmem_cache *); -int __kmem_cache_shrink(struct kmem_cache *, bool); +int __kmem_cache_shrink(struct kmem_cache *); +void __kmemcg_cache_deactivate(struct kmem_cache *s); void slab_kmem_cache_release(struct kmem_cache *); struct seq_file; diff --git a/mm/slab_common.c b/mm/slab_common.c index 274697e1a42a..59e41bb81575 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -646,7 +646,7 @@ void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg) if (!c) continue; - __kmem_cache_shrink(c, true); + __kmemcg_cache_deactivate(c); arr->entries[idx] = NULL; } mutex_unlock(&slab_mutex); @@ -794,7 +794,7 @@ int kmem_cache_shrink(struct kmem_cache *cachep) get_online_cpus(); get_online_mems(); kasan_cache_shrink(cachep); - ret = __kmem_cache_shrink(cachep, false); + ret = __kmem_cache_shrink(cachep); put_online_mems(); put_online_cpus(); return ret; diff --git a/mm/slob.c b/mm/slob.c index 5ec158054ffe..eac04d4357ec 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -634,7 +634,7 @@ void __kmem_cache_release(struct kmem_cache *c) { } -int __kmem_cache_shrink(struct kmem_cache *d, bool deactivate) +int __kmem_cache_shrink(struct kmem_cache *d) { return 0; } diff --git a/mm/slub.c b/mm/slub.c index 03b012bcb5fa..8a4591526f37 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3894,7 +3894,7 @@ EXPORT_SYMBOL(kfree); * being allocated from last increasing the chance that the last objects * are freed in them. */ -int __kmem_cache_shrink(struct kmem_cache *s, bool deactivate) +int __kmem_cache_shrink(struct kmem_cache *s) { int node; int i; @@ -3906,21 +3906,6 @@ int __kmem_cache_shrink(struct kmem_cache *s, bool deactivate) unsigned long flags; int ret = 0; - if (deactivate) { - /* - * Disable empty slabs caching. Used to avoid pinning offline - * memory cgroups by kmem pages that can be freed. - */ - s->cpu_partial = 0; - s->min_partial = 0; - - /* - * s->cpu_partial is checked locklessly (see put_cpu_partial), - * so we have to make sure the change is visible. - */ - synchronize_sched(); - } - flush_all(s); for_each_kmem_cache_node(s, node, n) { INIT_LIST_HEAD(&discard); @@ -3971,13 +3956,33 @@ int __kmem_cache_shrink(struct kmem_cache *s, bool deactivate) return ret; } +#ifdef CONFIG_MEMCG +void __kmemcg_cache_deactivate(struct kmem_cache *s) +{ + /* + * Disable empty slabs caching. Used to avoid pinning offline + * memory cgroups by kmem pages that can be freed. + */ + s->cpu_partial = 0; + s->min_partial = 0; + + /* + * s->cpu_partial is checked locklessly (see put_cpu_partial), so + * we have to make sure the change is visible. + */ + synchronize_sched(); + + __kmem_cache_shrink(s); +} +#endif + static int slab_mem_going_offline_callback(void *arg) { struct kmem_cache *s; mutex_lock(&slab_mutex); list_for_each_entry(s, &slab_caches, list) - __kmem_cache_shrink(s, false); + __kmem_cache_shrink(s); mutex_unlock(&slab_mutex); return 0; -- 2.20.1