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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.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
Mel Gorman 2016-07-28 15:45:53 -07:00 committed by Linus Torvalds
parent 38087d9b03
commit 79dafcdca3
1 changed files with 14 additions and 8 deletions
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22
mm/vmscan.c
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@ -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
* 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
* scan then give up on it.
*/
@ -2571,6 +2563,7 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
unsigned long nr_soft_scanned;
gfp_t orig_mask;
enum zone_type classzone_idx;
pg_data_t *last_pgdat = NULL;
/*
* 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)
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
* and returns the number of reclaimed pages and
@ -2644,6 +2646,10 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
/* 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);
}