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>

1 files changed, 2 insertions, 9 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index feb803bf3443..1a735fad2a13 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -242,15 +242,8 @@ void shake_page(struct page *p, int access)
          * Only call shrink_node_slabs here (which would also shrink
          * other caches) if access is not potentially fatal.
          */
-        if (access) {
-                int nr;
-                int nid = page_to_nid(p);
-                do {
-                        nr = shrink_node_slabs(GFP_KERNEL, nid, 1000, 1000);
-                        if (page_count(p) == 1)
-                                break;
-                } while (nr > 10);
-        }
+        if (access)
+                drop_slab_node(page_to_nid(p));
 }
 EXPORT_SYMBOL_GPL(shake_page);