vmscan: per memory cgroup slab shrinkers
This patch adds SHRINKER_MEMCG_AWARE flag. If a shrinker has this flag
set, it will be called per memory cgroup. The memory cgroup to scan
objects from is passed in shrink_control->memcg. If the memory cgroup
is NULL, a memcg aware shrinker is supposed to scan objects from the
global list. Unaware shrinkers are only called on global pressure with
memcg=NULL.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index f4aee75..4fcacd9 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -20,6 +20,9 @@
/* current node being shrunk (for NUMA aware shrinkers) */
int nid;
+
+ /* current memcg being shrunk (for memcg aware shrinkers) */
+ struct mem_cgroup *memcg;
};
#define SHRINK_STOP (~0UL)
@@ -61,7 +64,8 @@
#define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
/* Flags */
-#define SHRINKER_NUMA_AWARE (1 << 0)
+#define SHRINKER_NUMA_AWARE (1 << 0)
+#define SHRINKER_MEMCG_AWARE (1 << 1)
extern int register_shrinker(struct shrinker *);
extern void unregister_shrinker(struct shrinker *);