From b6ecd2dea4435a771a99c497a6ac5df6d3618c5a Mon Sep 17 00:00:00 2001 From: Vladimir Davydov Date: Thu, 17 Mar 2016 14:18:33 -0700 Subject: [PATCH] mm: memcontrol: zap memcg_kmem_online helper As kmem accounting is now either enabled for all cgroups or disabled system-wide, there's no point in having memcg_kmem_online() helper - instead one can use memcg_kmem_enabled() and mem_cgroup_online(), as shrink_slab() now does. There are only two places left where this helper is used - __memcg_kmem_charge() and memcg_create_kmem_cache(). The former can only be called if memcg_kmem_enabled() returned true. Since the cgroup it operates on is online, mem_cgroup_is_root() check will be enough. memcg_create_kmem_cache() can't use mem_cgroup_online() helper instead of memcg_kmem_online(), because it relies on the fact that in memcg_offline_kmem() memcg->kmem_state is changed before memcg_deactivate_kmem_caches() is called, but there we can just open-code the check. Signed-off-by: Vladimir Davydov Acked-by: Johannes Weiner Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 10 ---------- mm/memcontrol.c | 2 +- mm/slab_common.c | 2 +- 3 files changed, 2 insertions(+), 12 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index d6300313b298..bc8e4e22f58f 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -795,11 +795,6 @@ static inline bool memcg_kmem_enabled(void) return static_branch_unlikely(&memcg_kmem_enabled_key); } -static inline bool memcg_kmem_online(struct mem_cgroup *memcg) -{ - return memcg->kmem_state == KMEM_ONLINE; -} - /* * In general, we'll do everything in our power to not incur in any overhead * for non-memcg users for the kmem functions. Not even a function call, if we @@ -909,11 +904,6 @@ static inline bool memcg_kmem_enabled(void) return false; } -static inline bool memcg_kmem_online(struct mem_cgroup *memcg) -{ - return false; -} - static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order) { return 0; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 28d1b1e9d4fb..341bf86d26c2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2346,7 +2346,7 @@ int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order) int ret = 0; memcg = get_mem_cgroup_from_mm(current->mm); - if (memcg_kmem_online(memcg)) + if (!mem_cgroup_is_root(memcg)) ret = __memcg_kmem_charge_memcg(page, gfp, order, memcg); css_put(&memcg->css); return ret; diff --git a/mm/slab_common.c b/mm/slab_common.c index 6afb2263a5c5..8addc3c4df37 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -510,7 +510,7 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, * The memory cgroup could have been offlined while the cache * creation work was pending. */ - if (!memcg_kmem_online(memcg)) + if (memcg->kmem_state != KMEM_ONLINE) goto out_unlock; idx = memcg_cache_id(memcg); -- 2.20.1