The patch titled
compaction: checks correct fragmentation index
has been added to the -mm tree. Its filename is
compaction-checks-correct-fragmentation-index.patch
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------------------------------------------------------
Subject: compaction: checks correct fragmentation index
From: Shaohua Li <shaohua.li@xxxxxxxxx>
fragmentation_index() returns -1000 when the allocation might succeed
This doesn't match the comment and code in compaction_suitable(). I
thought compaction_suitable should return COMPACT_PARTIAL in -1000
case, because in this case allocation could succeed depending on
watermarks.
The impact of this is that compaction starts and compact_finished() is
called which rechecks the watermarks and the free lists. It should have
the same result in that compaction should not start but is more expensive.
Acked-by: Mel Gorman <mel@xxxxxxxxx>
Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/compaction.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff -puN mm/compaction.c~compaction-checks-correct-fragmentation-index mm/compaction.c
--- a/mm/compaction.c~compaction-checks-correct-fragmentation-index
+++ a/mm/compaction.c
@@ -480,7 +480,8 @@ unsigned long compaction_suitable(struct
* fragmentation index determines if allocation failures are due to
* low memory or external fragmentation
*
- * index of -1 implies allocations might succeed dependingon watermarks
+ * index of -1000 implies allocations might succeed depending on
+ * watermarks
* index towards 0 implies failure is due to lack of memory
* index towards 1000 implies failure is due to fragmentation
*
@@ -490,7 +491,8 @@ unsigned long compaction_suitable(struct
if (fragindex >= 0 && fragindex <= sysctl_extfrag_threshold)
return COMPACT_SKIPPED;
- if (fragindex == -1 && zone_watermark_ok(zone, order, watermark, 0, 0))
+ if (fragindex == -1000 && zone_watermark_ok(zone, order, watermark,
+ 0, 0))
return COMPACT_PARTIAL;
return COMPACT_CONTINUE;
_
Patches currently in -mm which might be from shaohua.li@xxxxxxxxx are
compaction-checks-correct-fragmentation-index.patch
linux-next.patch
intel_idle-fix-api-misuse.patch
intel_idle-disable-auto_demotion-for-hotplugged-cpus.patch
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