From 073ee1c6cd11cd190f4d0da84d9b4ba79d7b9e70 Mon Sep 17 00:00:00 2001 From: Vladimir Davydov Date: Wed, 4 Jun 2014 16:08:23 -0700 Subject: [PATCH] memcg: get rid of memcg_create_cache_name Instead of calling back to memcontrol.c from kmem_cache_create_memcg in order to just create the name of a per memcg cache, let's allocate it in place. We only need to pass the memcg name to kmem_cache_create_memcg for that - everything else can be done in slab_common.c. Signed-off-by: Vladimir Davydov Acked-by: Michal Hocko Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 2 -- include/linux/slab.h | 3 ++- mm/memcontrol.c | 33 +++++++++------------------------ mm/slab_common.c | 7 +++++-- 4 files changed, 16 insertions(+), 29 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 1fa23244fe37..dfc2929a3877 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -492,8 +492,6 @@ void __memcg_kmem_uncharge_pages(struct page *page, int order); int memcg_cache_id(struct mem_cgroup *memcg); -char *memcg_create_cache_name(struct mem_cgroup *memcg, - struct kmem_cache *root_cache); int memcg_alloc_cache_params(struct mem_cgroup *memcg, struct kmem_cache *s, struct kmem_cache *root_cache); void memcg_free_cache_params(struct kmem_cache *s); diff --git a/include/linux/slab.h b/include/linux/slab.h index ecbec9ccb80d..86e5b26fbdab 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -117,7 +117,8 @@ struct kmem_cache *kmem_cache_create(const char *, size_t, size_t, void (*)(void *)); #ifdef CONFIG_MEMCG_KMEM struct kmem_cache *kmem_cache_create_memcg(struct mem_cgroup *, - struct kmem_cache *); + struct kmem_cache *, + const char *); #endif void kmem_cache_destroy(struct kmem_cache *); int kmem_cache_shrink(struct kmem_cache *); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 971d7b643f6e..7df7f599e3df 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3095,29 +3095,6 @@ int memcg_update_cache_size(struct kmem_cache *s, int num_groups) return 0; } -char *memcg_create_cache_name(struct mem_cgroup *memcg, - struct kmem_cache *root_cache) -{ - static char *buf; - - /* - * We need a mutex here to protect the shared buffer. Since this is - * expected to be called only on cache creation, we can employ the - * slab_mutex for that purpose. - */ - lockdep_assert_held(&slab_mutex); - - if (!buf) { - buf = kmalloc(NAME_MAX + 1, GFP_KERNEL); - if (!buf) - return NULL; - } - - cgroup_name(memcg->css.cgroup, buf, NAME_MAX + 1); - return kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name, - memcg_cache_id(memcg), buf); -} - int memcg_alloc_cache_params(struct mem_cgroup *memcg, struct kmem_cache *s, struct kmem_cache *root_cache) { @@ -3158,6 +3135,7 @@ void memcg_free_cache_params(struct kmem_cache *s) static void memcg_kmem_create_cache(struct mem_cgroup *memcg, struct kmem_cache *root_cache) { + static char *memcg_name_buf; /* protected by memcg_slab_mutex */ struct kmem_cache *cachep; int id; @@ -3173,7 +3151,14 @@ static void memcg_kmem_create_cache(struct mem_cgroup *memcg, if (cache_from_memcg_idx(root_cache, id)) return; - cachep = kmem_cache_create_memcg(memcg, root_cache); + if (!memcg_name_buf) { + memcg_name_buf = kmalloc(NAME_MAX + 1, GFP_KERNEL); + if (!memcg_name_buf) + return; + } + + cgroup_name(memcg->css.cgroup, memcg_name_buf, NAME_MAX + 1); + cachep = kmem_cache_create_memcg(memcg, root_cache, memcg_name_buf); /* * If we could not create a memcg cache, do not complain, because * that's not critical at all as we can always proceed with the root diff --git a/mm/slab_common.c b/mm/slab_common.c index 7e348cff814d..32175617cb75 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -264,13 +264,15 @@ EXPORT_SYMBOL(kmem_cache_create); * kmem_cache_create_memcg - Create a cache for a memory cgroup. * @memcg: The memory cgroup the new cache is for. * @root_cache: The parent of the new cache. + * @memcg_name: The name of the memory cgroup (used for naming the new cache). * * This function attempts to create a kmem cache that will serve allocation * requests going from @memcg to @root_cache. The new cache inherits properties * from its parent. */ struct kmem_cache *kmem_cache_create_memcg(struct mem_cgroup *memcg, - struct kmem_cache *root_cache) + struct kmem_cache *root_cache, + const char *memcg_name) { struct kmem_cache *s = NULL; char *cache_name; @@ -280,7 +282,8 @@ struct kmem_cache *kmem_cache_create_memcg(struct mem_cgroup *memcg, mutex_lock(&slab_mutex); - cache_name = memcg_create_cache_name(memcg, root_cache); + cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name, + memcg_cache_id(memcg), memcg_name); if (!cache_name) goto out_unlock; -- 2.20.1