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authorRoman Gushchin <guro@fb.com>2020-08-06 23:21:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-07 11:33:25 -0700
commit9855609bde03e2472b99a95e869d29ee1e78a751 (patch)
treeefc534e04c3e1acbc1dcb4dcb681c30bd072fc59 /mm/slub.c
parent0f876e4dc55db5fafef774917fd66e1373c0f390 (diff)
mm: memcg/slab: use a single set of kmem_caches for all accounted allocations
This is fairly big but mostly red patch, which makes all accounted slab allocations use a single set of kmem_caches instead of creating a separate set for each memory cgroup. Because the number of non-root kmem_caches is now capped by the number of root kmem_caches, there is no need to shrink or destroy them prematurely. They can be perfectly destroyed together with their root counterparts. This allows to dramatically simplify the management of non-root kmem_caches and delete a ton of code. This patch performs the following changes: 1) introduces memcg_params.memcg_cache pointer to represent the kmem_cache which will be used for all non-root allocations 2) reuses the existing memcg kmem_cache creation mechanism to create memcg kmem_cache on the first allocation attempt 3) memcg kmem_caches are named <kmemcache_name>-memcg, e.g. dentry-memcg 4) simplifies memcg_kmem_get_cache() to just return memcg kmem_cache or schedule it's creation and return the root cache 5) removes almost all non-root kmem_cache management code (separate refcounter, reparenting, shrinking, etc) 6) makes slab debugfs to display root_mem_cgroup css id and never show :dead and :deact flags in the memcg_slabinfo attribute. Following patches in the series will simplify the kmem_cache creation. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20200623174037.3951353-13-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slub.c')
-rw-r--r--mm/slub.c38
1 files changed, 5 insertions, 33 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 47e63b1100d4..44a48a08a691 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4204,36 +4204,6 @@ int __kmem_cache_shrink(struct kmem_cache *s)
return ret;
}
-#ifdef CONFIG_MEMCG
-void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s)
-{
- /*
- * Called with all the locks held after a sched RCU grace period.
- * Even if @s becomes empty after shrinking, we can't know that @s
- * doesn't have allocations already in-flight and thus can't
- * destroy @s until the associated memcg is released.
- *
- * However, let's remove the sysfs files for empty caches here.
- * Each cache has a lot of interface files which aren't
- * particularly useful for empty draining caches; otherwise, we can
- * easily end up with millions of unnecessary sysfs files on
- * systems which have a lot of memory and transient cgroups.
- */
- if (!__kmem_cache_shrink(s))
- sysfs_slab_remove(s);
-}
-
-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.
- */
- slub_set_cpu_partial(s, 0);
- s->min_partial = 0;
-}
-#endif /* CONFIG_MEMCG */
-
static int slab_mem_going_offline_callback(void *arg)
{
struct kmem_cache *s;
@@ -4390,7 +4360,7 @@ static struct kmem_cache * __init bootstrap(struct kmem_cache *static_cache)
}
slab_init_memcg_params(s);
list_add(&s->list, &slab_caches);
- memcg_link_cache(s, NULL);
+ memcg_link_cache(s);
return s;
}
@@ -4458,7 +4428,8 @@ __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
s->object_size = max(s->object_size, size);
s->inuse = max(s->inuse, ALIGN(size, sizeof(void *)));
- for_each_memcg_cache(c, s) {
+ c = memcg_cache(s);
+ if (c) {
c->object_size = s->object_size;
c->inuse = max(c->inuse, ALIGN(size, sizeof(void *)));
}
@@ -5591,7 +5562,8 @@ static ssize_t slab_attr_store(struct kobject *kobj,
* directly either failed or succeeded, in which case we loop
* through the descendants with best-effort propagation.
*/
- for_each_memcg_cache(c, s)
+ c = memcg_cache(s);
+ if (c)
attribute->store(c, buf, len);
mutex_unlock(&slab_mutex);
}