Commit 4d5c8aed authored by Roman Gushchin's avatar Roman Gushchin Committed by Dennis Zhou
Browse files

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: default avatarRoman Gushchin <guro@fb.com>
Signed-off-by: default avatarDennis Zhou <dennis@kernel.org>
parent 0f0cace3

include/linux/memcontrol.h

+5 −0
Original line number Diff line number Diff line
@@ -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)

mm/memcontrol.c

+5 −0
Original line number Diff line number Diff line
@@ -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,