Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

mm: vmscan: fix inappropriate zone congestion clearing

Browse source 
commit c702418f8a ("mm: vmscan: do not keep kswapd looping forever due
to individual uncompactable zones") removed zone watermark checks from
the compaction code in kswapd but left in the zone congestion clearing,
which now happens unconditionally on higher order reclaim.

This messes up the reclaim throttling logic for zones with
dirty/writeback pages, where zones should only lose their congestion
status when their watermarks have been restored.

Remove the clearing from the zone compaction section entirely.  The
preliminary zone check and the reclaim loop in kswapd will clear it if
the zone is considered balanced.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2012-12-06 15:23:25 -05:00 committed by Linus Torvalds
parent 684c9aaebb
commit ed23ec4f0a
1 changed files with 0 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
mm/vmscan.c
View file

@ -2827,9 +2827,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
if (zone_watermark_ok(zone, order,
low_wmark_pages(zone), *classzone_idx, 0))
zones_need_compaction = 0;
/* If balanced, clear the congested flag */
zone_clear_flag(zone, ZONE_CONGESTED);
}
if (zones_need_compaction)