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authorDavid Rientjes <rientjes@google.com>2012-12-12 13:51:57 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-12 17:38:34 -0800
commit68ae564bbac8eb9ed54ddd2529b0e29ee190b355 (patch)
tree5cef83b5fa072f62091552457e7d0319ce170b98
parent05b0afd73d04109d87f00ccd39f099e217c37263 (diff)
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: David Rientjes <rientjes@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Glauber Costa <glommer@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/memcontrol.h9
-rw-r--r--mm/memcontrol.c6
2 files changed, 12 insertions, 3 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 11ddc7ffeba..e98a74c0c9c 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -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
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 49d86d06e1d..7f0e3571df7 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -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