shrinker: add node awareness

Pass the node of the current zone being reclaimed to shrink_slab(),
allowing the shrinker control nodemask to be set appropriately for node
aware shrinkers.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 21a3f72..65f36d7 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -692,6 +692,9 @@
 				.gfp_mask = GFP_KERNEL,
 				.nr_to_scan = 0,
 			};
+
+			nodes_setall(sc.nodes_to_scan);
+
 			ret = ashmem_shrink(&ashmem_shrinker, &sc);
 			sc.nr_to_scan = ret;
 			ashmem_shrink(&ashmem_shrinker, &sc);
diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index c00e055..9fd702f 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -44,6 +44,7 @@
 		.gfp_mask = GFP_KERNEL,
 	};
 
+	nodes_setall(shrink.nodes_to_scan);
 	do {
 		nr_objects = shrink_slab(&shrink, 1000, 1000);
 	} while (nr_objects > 10);
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 884e762..76f520c 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -16,6 +16,9 @@
 
 	/* How many slab objects shrinker() should scan and try to reclaim */
 	unsigned long nr_to_scan;
+
+	/* shrink from these nodes */
+	nodemask_t nodes_to_scan;
 };
 
 #define SHRINK_STOP (~0UL)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index d84c5e5..baa4e0a 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -248,10 +248,12 @@
 	 */
 	if (access) {
 		int nr;
+		int nid = page_to_nid(p);
 		do {
 			struct shrink_control shrink = {
 				.gfp_mask = GFP_KERNEL,
 			};
+			node_set(nid, shrink.nodes_to_scan);
 
 			nr = shrink_slab(&shrink, 1000, 1000);
 			if (page_count(p) == 1)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4d4e859..fe0d5c4 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2374,12 +2374,16 @@
 		 */
 		if (global_reclaim(sc)) {
 			unsigned long lru_pages = 0;
+
+			nodes_clear(shrink->nodes_to_scan);
 			for_each_zone_zonelist(zone, z, zonelist,
 					gfp_zone(sc->gfp_mask)) {
 				if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
 					continue;
 
 				lru_pages += zone_reclaimable_pages(zone);
+				node_set(zone_to_nid(zone),
+					 shrink->nodes_to_scan);
 			}
 
 			shrink_slab(shrink, sc->nr_scanned, lru_pages);
@@ -2836,6 +2840,8 @@
 		return true;
 
 	shrink_zone(zone, sc);
+	nodes_clear(shrink.nodes_to_scan);
+	node_set(zone_to_nid(zone), shrink.nodes_to_scan);
 
 	reclaim_state->reclaimed_slab = 0;
 	nr_slab = shrink_slab(&shrink, sc->nr_scanned, lru_pages);
@@ -3544,10 +3550,9 @@
 		 * number of slab pages and shake the slab until it is reduced
 		 * by the same nr_pages that we used for reclaiming unmapped
 		 * pages.
-		 *
-		 * Note that shrink_slab will free memory on all zones and may
-		 * take a long time.
 		 */
+		nodes_clear(shrink.nodes_to_scan);
+		node_set(zone_to_nid(zone), shrink.nodes_to_scan);
 		for (;;) {
 			unsigned long lru_pages = zone_reclaimable_pages(zone);