From f1008365bbe4931d6a94dcfc11cf4cdada359664 Mon Sep 17 00:00:00 2001 From: Vladimir Davydov Date: Thu, 12 Feb 2015 14:59:29 -0800 Subject: [PATCH] slab: use css id for naming per memcg caches Currently, we use mem_cgroup->kmemcg_id to guarantee kmem_cache->name uniqueness. This is correct, because kmemcg_id is only released on css free after destroying all per memcg caches. However, I am going to change that and release kmemcg_id on css offline, because it is not wise to keep it for so long, wasting valuable entries of memcg_cache_params->memcg_caches arrays. Therefore, to preserve cache name uniqueness, let us switch to css->id. Signed-off-by: Vladimir Davydov Cc: Johannes Weiner Cc: Michal Hocko Cc: Tejun Heo Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Dave Chinner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab_common.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index 989784bd88be..6087b1f9a385 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -488,6 +488,7 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, struct kmem_cache *root_cache) { static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */ + struct cgroup_subsys_state *css = mem_cgroup_css(memcg); struct memcg_cache_array *arr; struct kmem_cache *s = NULL; char *cache_name; @@ -510,10 +511,9 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, if (arr->entries[idx]) goto out_unlock; - cgroup_name(mem_cgroup_css(memcg)->cgroup, - memcg_name_buf, sizeof(memcg_name_buf)); + cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf)); cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name, - idx, memcg_name_buf); + css->id, memcg_name_buf); if (!cache_name) goto out_unlock; -- 2.39.2