memcontrol: add vm_match_cgroup()
mm_cgroup() is exclusively used to test whether an mm's mem_cgroup pointer
is pointing to a specific cgroup. Instead of returning the pointer, we can
just do the test itself in a new macro:
vm_match_cgroup(mm, cgroup)
returns non-zero if the mm's mem_cgroup points to cgroup. Otherwise it
returns zero.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5c2c702..6bded84 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -399,7 +399,7 @@
int ret;
task_lock(task);
- ret = task->mm && mm_cgroup(task->mm) == mem;
+ ret = task->mm && vm_match_cgroup(task->mm, mem);
task_unlock(task);
return ret;
}