Commit 79dafcdc authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds

mm, vmscan: by default have direct reclaim only shrink once per node

Direct reclaim iterates over all zones in the zonelist and shrinking
them but this is in conflict with node-based reclaim.  In the default
case, only shrink once per node.

Link: http://lkml.kernel.org/r/1467970510-21195-11-git-send-email-mgorman@techsingularity.netSigned-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 38087d9b
...@@ -2552,14 +2552,6 @@ static inline bool compaction_ready(struct zone *zone, int order, int classzone_ ...@@ -2552,14 +2552,6 @@ static inline bool compaction_ready(struct zone *zone, int order, int classzone_
* try to reclaim pages from zones which will satisfy the caller's allocation * try to reclaim pages from zones which will satisfy the caller's allocation
* request. * request.
* *
* We reclaim from a zone even if that zone is over high_wmark_pages(zone).
* Because:
* a) The caller may be trying to free *extra* pages to satisfy a higher-order
* allocation or
* b) The target zone may be at high_wmark_pages(zone) but the lower zones
* must go *over* high_wmark_pages(zone) to satisfy the `incremental min'
* zone defense algorithm.
*
* If a zone is deemed to be full of pinned pages then just give it a light * If a zone is deemed to be full of pinned pages then just give it a light
* scan then give up on it. * scan then give up on it.
*/ */
...@@ -2571,6 +2563,7 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) ...@@ -2571,6 +2563,7 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
unsigned long nr_soft_scanned; unsigned long nr_soft_scanned;
gfp_t orig_mask; gfp_t orig_mask;
enum zone_type classzone_idx; enum zone_type classzone_idx;
pg_data_t *last_pgdat = NULL;
/* /*
* If the number of buffer_heads in the machine exceeds the maximum * If the number of buffer_heads in the machine exceeds the maximum
...@@ -2629,6 +2622,15 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) ...@@ -2629,6 +2622,15 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
continue; continue;
} }
/*
* Shrink each node in the zonelist once. If the
* zonelist is ordered by zone (not the default) then a
* node may be shrunk multiple times but in that case
* the user prefers lower zones being preserved.
*/
if (zone->zone_pgdat == last_pgdat)
continue;
/* /*
* This steals pages from memory cgroups over softlimit * This steals pages from memory cgroups over softlimit
* and returns the number of reclaimed pages and * and returns the number of reclaimed pages and
...@@ -2644,6 +2646,10 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) ...@@ -2644,6 +2646,10 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
/* need some check for avoid more shrink_zone() */ /* need some check for avoid more shrink_zone() */
} }
/* See comment about same check for global reclaim above */
if (zone->zone_pgdat == last_pgdat)
continue;
last_pgdat = zone->zone_pgdat;
shrink_node(zone->zone_pgdat, sc, classzone_idx); shrink_node(zone->zone_pgdat, sc, classzone_idx);
} }
......
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