mm: vmscan: remove all_unreclaimable()
Direct reclaim currently calls shrink_zones() to reclaim all members of
a zonelist, and if that wasn't successful it does another pass through
the same zonelist to check overall reclaimability.
Just check reclaimability in shrink_zones() directly and propagate the
result through the return value. Then remove all_unreclaimable().
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6f43df4..74a9e0a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2244,9 +2244,10 @@
}
}
-static void shrink_zone(struct zone *zone, struct scan_control *sc)
+static bool shrink_zone(struct zone *zone, struct scan_control *sc)
{
unsigned long nr_reclaimed, nr_scanned;
+ bool reclaimable = false;
do {
struct mem_cgroup *root = sc->target_mem_cgroup;
@@ -2290,8 +2291,13 @@
sc->nr_scanned - nr_scanned,
sc->nr_reclaimed - nr_reclaimed);
+ if (sc->nr_reclaimed - nr_reclaimed)
+ reclaimable = true;
+
} while (should_continue_reclaim(zone, sc->nr_reclaimed - nr_reclaimed,
sc->nr_scanned - nr_scanned, sc));
+
+ return reclaimable;
}
/* Returns true if compaction should go ahead for a high-order request */
@@ -2340,8 +2346,10 @@
*
* If a zone is deemed to be full of pinned pages then just give it a light
* scan then give up on it.
+ *
+ * Returns true if a zone was reclaimable.
*/
-static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
+static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
{
struct zoneref *z;
struct zone *zone;
@@ -2354,6 +2362,7 @@
.gfp_mask = sc->gfp_mask,
};
enum zone_type requested_highidx = gfp_zone(sc->gfp_mask);
+ bool reclaimable = false;
/*
* If the number of buffer_heads in the machine exceeds the maximum
@@ -2414,10 +2423,17 @@
&nr_soft_scanned);
sc->nr_reclaimed += nr_soft_reclaimed;
sc->nr_scanned += nr_soft_scanned;
+ if (nr_soft_reclaimed)
+ reclaimable = true;
/* need some check for avoid more shrink_zone() */
}
- shrink_zone(zone, sc);
+ if (shrink_zone(zone, sc))
+ reclaimable = true;
+
+ if (global_reclaim(sc) &&
+ !reclaimable && zone_reclaimable(zone))
+ reclaimable = true;
}
/*
@@ -2439,26 +2455,8 @@
* promoted it to __GFP_HIGHMEM.
*/
sc->gfp_mask = orig_mask;
-}
-/* All zones in zonelist are unreclaimable? */
-static bool all_unreclaimable(struct zonelist *zonelist,
- struct scan_control *sc)
-{
- struct zoneref *z;
- struct zone *zone;
-
- for_each_zone_zonelist_nodemask(zone, z, zonelist,
- gfp_zone(sc->gfp_mask), sc->nodemask) {
- if (!populated_zone(zone))
- continue;
- if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
- continue;
- if (zone_reclaimable(zone))
- return false;
- }
-
- return true;
+ return reclaimable;
}
/*
@@ -2482,6 +2480,7 @@
{
unsigned long total_scanned = 0;
unsigned long writeback_threshold;
+ bool zones_reclaimable;
delayacct_freepages_start();
@@ -2492,7 +2491,7 @@
vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup,
sc->priority);
sc->nr_scanned = 0;
- shrink_zones(zonelist, sc);
+ zones_reclaimable = shrink_zones(zonelist, sc);
total_scanned += sc->nr_scanned;
if (sc->nr_reclaimed >= sc->nr_to_reclaim)
@@ -2532,8 +2531,8 @@
if (sc->compaction_ready)
return 1;
- /* top priority shrink_zones still had more to do? don't OOM, then */
- if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc))
+ /* Any of the zones still reclaimable? Don't OOM. */
+ if (zones_reclaimable)
return 1;
return 0;