From 4d5c8aedc8aa6a1f5d1b06eb4f5517dc60dd9440 Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Wed, 2 Jun 2021 18:09:30 -0700 Subject: [PATCH] mm, memcg: introduce mem_cgroup_kmem_disabled() Introduce a new mem_cgroup_kmem_disabled() helper, similar to mem_cgroup_disabled(), to check whether the kernel memory accounting is off. A user could disable it using a boot option to eliminate some associated costs. The helper can be used outside of memcontrol.c to dynamically disable the kmem-related code. The returned value is stable after the kernel initialization is finished. Signed-off-by: Roman Gushchin Signed-off-by: Dennis Zhou --- include/linux/memcontrol.h | 5 +++++ mm/memcontrol.c | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 0c04d39a7967..8ef51c58f470 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1583,6 +1583,7 @@ static inline void memcg_set_shrinker_bit(struct mem_cgroup *memcg, #endif #ifdef CONFIG_MEMCG_KMEM +bool mem_cgroup_kmem_disabled(void); int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order); void __memcg_kmem_uncharge_page(struct page *page, int order); @@ -1636,6 +1637,10 @@ static inline int memcg_cache_id(struct mem_cgroup *memcg) struct mem_cgroup *mem_cgroup_from_obj(void *p); #else +static inline bool mem_cgroup_kmem_disabled(void) +{ + return true; +} static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e6203ee24a11..1fa9b00ec71d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -255,6 +255,11 @@ struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr) #ifdef CONFIG_MEMCG_KMEM extern spinlock_t css_set_lock; +bool mem_cgroup_kmem_disabled(void) +{ + return cgroup_memory_nokmem; +} + static int __memcg_kmem_charge(struct mem_cgroup *memcg, gfp_t gfp, unsigned int nr_pages); static void __memcg_kmem_uncharge(struct mem_cgroup *memcg,