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. This patch distinguishes the premature ending condition. Further distinguishing the exact reason seems unnecessary for now.
Signed-off-by: Vlastimil Babka <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Mel Gorman <[email protected]> Cc: David Rientjes <[email protected]> --- include/linux/compaction.h | 1 + include/trace/events/compaction.h | 3 ++- mm/compaction.c | 4 +++- 3 files changed, 6 insertions(+), 2 deletions(-) diff --git a/include/linux/compaction.h b/include/linux/compaction.h index aa8f61c..50c9580 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -15,6 +15,7 @@ /* For more detailed tracepoint output */ #define COMPACT_NO_SUITABLE_PAGE 5 #define COMPACT_NOT_SUITABLE_ZONE 6 +#define COMPACT_CONTENDED 7 /* When adding new state, please change compaction_status_string, too */ /* Used to signal whether compaction detected need_sched() or lock contention */ diff --git a/include/trace/events/compaction.h b/include/trace/events/compaction.h index 8daa8fa..5604994 100644 --- a/include/trace/events/compaction.h +++ b/include/trace/events/compaction.h @@ -16,7 +16,8 @@ EM( COMPACT_PARTIAL, "partial") \ EM( COMPACT_COMPLETE, "complete") \ EM( COMPACT_NO_SUITABLE_PAGE, "no_suitable_page") \ - EMe(COMPACT_NOT_SUITABLE_ZONE, "not_suitable_zone") + EM( COMPACT_NOT_SUITABLE_ZONE, "not_suitable_zone") \ + EMe(COMPACT_CONTENDED, "contended") #ifdef CONFIG_ZONE_DMA #define IFDEF_ZONE_DMA(X) X diff --git a/mm/compaction.c b/mm/compaction.c index 7d6ef6e..75a0aca 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1133,7 +1133,7 @@ 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 (cc->free_pfn <= cc->migrate_pfn) { @@ -1204,6 +1204,8 @@ static int compact_finished(struct zone *zone, struct compact_control *cc, trace_mm_compaction_finished(zone, cc->order, ret); if (ret == COMPACT_NO_SUITABLE_PAGE) ret = COMPACT_CONTINUE; + else if (ret == COMPACT_CONTENDED) + ret = COMPACT_PARTIAL; return ret; } -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
