Commit c9fc5864 authored by Tejun Heo's avatar Tejun Heo Committed by Linus Torvalds
Browse files

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: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarVladimir Davydov <vdavydov.dev@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 510ded33
......@@ -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)
......
......@@ -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;
......
......@@ -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;
......
......@@ -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;
}
......
......@@ -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;
......
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