[PATCH v6 11/31] shrinker: add node awareness

Glauber Costa
2013-05-12T18:13:32Z

From: Dave Chinner <dchinner@redhat.com>

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.

[ v3: update ashmem ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
---
drivers/staging/android/ashmem.c | 3 +++
fs/drop_caches.c | 1 +
include/linux/shrinker.h | 3 +++
mm/memory-failure.c | 2 ++
mm/vmscan.c | 12 +++++++++---
5 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index e681bdd..3240d34 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -692,6 +692,9 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
.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 f23d2a7..c3f44e7 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -44,6 +44,7 @@ static void drop_slab(void)
.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 c277b4e..98be3ab 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -16,6 +16,9 @@ struct shrink_control {

/* How many slab objects shrinker() should scan and try to reclaim */
long nr_to_scan;
+
+ /* shrink from these nodes */
+ nodemask_t nodes_to_scan;
};

/*
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ceb0c7f..86788ff 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -248,10 +248,12 @@ void shake_page(struct page *p, int access)
*/
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 fd4639c..35a6a9b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2198,15 +2198,20 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
*/
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);
+
if (reclaim_state) {
sc->nr_reclaimed += reclaim_state->reclaimed_slab;
reclaim_state->reclaimed_slab = 0;
@@ -2782,6 +2787,8 @@ loop_again:
shrink_zone(zone, &sc);

reclaim_state->reclaimed_slab = 0;
+ nodes_clear(shrink.nodes_to_scan);
+ node_set(zone_to_nid(zone), shrink.nodes_to_scan);
nr_slab = shrink_slab(&shrink, sc.nr_scanned, lru_pages);
sc.nr_reclaimed += reclaim_state->reclaimed_slab;

@@ -3367,10 +3374,9 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
* 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);

--
1.8.1.4