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authorVlastimil Babka <vbabka@suse.cz>2015-11-05 18:48:02 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-11-05 19:34:48 -0800
commit2d1e10412c2388ff9b6afc60536eaa195a419289 (patch)
treeb1a4d9b145a9c4442e51141b9fa17d25d8fa90fb /mm/compaction.c
parent1743d0506003f7db0602d120ecf63e2747af0d72 (diff)
downloadop-kernel-dev-2d1e10412c2388ff9b6afc60536eaa195a419289.zip
op-kernel-dev-2d1e10412c2388ff9b6afc60536eaa195a419289.tar.gz
mm, compaction: distinguish contended status in tracepoints
Compaction returns prematurely with COMPACT_PARTIAL when contended or has fatal signal pending. This is ok for the callers, but might be misleading in the traces, as the usual reason to return COMPACT_PARTIAL is that we think the allocation should succeed. After this patch we distinguish the premature ending condition in the mm_compaction_finished and mm_compaction_end tracepoints. The contended status covers the following reasons: - lock contention or need_resched() detected in async compaction - fatal signal pending - too many pages isolated in the zone (only for async compaction) Further distinguishing the exact reason seems unnecessary for now. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/compaction.c')
-rw-r--r--mm/compaction.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index a5849c4..de3e1e7 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1202,7 +1202,7 @@ static int __compact_finished(struct zone *zone, struct compact_control *cc,
unsigned long watermark;
if (cc->contended || fatal_signal_pending(current))
- return COMPACT_PARTIAL;
+ return COMPACT_CONTENDED;
/* Compaction run completes if the migrate and free scanner meet */
if (compact_scanners_met(cc)) {
@@ -1393,7 +1393,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
switch (isolate_migratepages(zone, cc)) {
case ISOLATE_ABORT:
- ret = COMPACT_PARTIAL;
+ ret = COMPACT_CONTENDED;
putback_movable_pages(&cc->migratepages);
cc->nr_migratepages = 0;
goto out;
@@ -1424,7 +1424,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
* and we want compact_finished() to detect it
*/
if (err == -ENOMEM && !compact_scanners_met(cc)) {
- ret = COMPACT_PARTIAL;
+ ret = COMPACT_CONTENDED;
goto out;
}
}
@@ -1477,6 +1477,9 @@ out:
trace_mm_compaction_end(start_pfn, cc->migrate_pfn,
cc->free_pfn, end_pfn, sync, ret);
+ if (ret == COMPACT_CONTENDED)
+ ret = COMPACT_PARTIAL;
+
return ret;
}
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