Commit 68ae564b authored by David Rientjes's avatar David Rientjes Committed by Linus Torvalds

mm, memcg: avoid unnecessary function call when memcg is disabled

While profiling numa/core v16 with cgroup_disable=memory on the command
line, I noticed mem_cgroup_count_vm_event() still showed up as high as
0.60% in perftop.

This occurs because the function is called extremely often even when memcg
is disabled.

To fix this, inline the check for mem_cgroup_disabled() so we avoid the
unnecessary function call if memcg is disabled.
Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: default avatarGlauber Costa <glommer@parallels.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 05b0afd7
......@@ -181,7 +181,14 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
gfp_t gfp_mask,
unsigned long *total_scanned);
void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx);
void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx);
static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
enum vm_event_item idx)
{
if (mem_cgroup_disabled())
return;
__mem_cgroup_count_vm_event(mm, idx);
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void mem_cgroup_split_huge_fixup(struct page *head);
#endif
......
......@@ -59,6 +59,8 @@
#include <trace/events/vmscan.h>
struct cgroup_subsys mem_cgroup_subsys __read_mostly;
EXPORT_SYMBOL(mem_cgroup_subsys);
#define MEM_CGROUP_RECLAIM_RETRIES 5
static struct mem_cgroup *root_mem_cgroup __read_mostly;
......@@ -1015,7 +1017,7 @@ void mem_cgroup_iter_break(struct mem_cgroup *root,
iter != NULL; \
iter = mem_cgroup_iter(NULL, iter, NULL))
void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
{
struct mem_cgroup *memcg;
......@@ -1040,7 +1042,7 @@ void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
out:
rcu_read_unlock();
}
EXPORT_SYMBOL(mem_cgroup_count_vm_event);
EXPORT_SYMBOL(__mem_cgroup_count_vm_event);
/**
* mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
......
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