Re: [PATCH 04/10] mm: zone_reclaim: compaction: reset before initializing the scan cursors

[Wanpeng Li <liwanp@linux.vnet.ibm.com>]

On Tue, Jul 16, 2013 at 03:41:48PM +0200, Andrea Arcangeli wrote:
>Correct the location where we reset the scan cursors, otherwise the
>first iteration of compaction (after restarting it) will only do a
>partial scan.
>
>Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
>Reviewed-by: Rik van Riel <riel@redhat.com>
>Acked-by: Mel Gorman <mgorman@suse.de>
>Acked-by: Rafael Aquini <aquini@redhat.com>

Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>

>---
> mm/compaction.c | 19 +++++++++++--------
> 1 file changed, 11 insertions(+), 8 deletions(-)
>
>diff --git a/mm/compaction.c b/mm/compaction.c
>index 525baaa..afaf692 100644
>--- a/mm/compaction.c
>+++ b/mm/compaction.c
>@@ -934,6 +934,17 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
> 	}
>
> 	/*
>+	 * Clear pageblock skip if there were failures recently and
>+	 * compaction is about to be retried after being
>+	 * deferred. kswapd does not do this reset and it will wait
>+	 * direct compaction to do so either when the cursor meets
>+	 * after one compaction pass is complete or if compaction is
>+	 * restarted after being deferred for a while.
>+	 */
>+	if ((compaction_restarting(zone, cc->order)) && !current_is_kswapd())
>+		__reset_isolation_suitable(zone);
>+
>+	/*
> 	 * Setup to move all movable pages to the end of the zone. Used cached
> 	 * information on where the scanners should start but check that it
> 	 * is initialised by ensuring the values are within zone boundaries.
>@@ -949,14 +960,6 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
> 		zone->compact_cached_migrate_pfn = cc->migrate_pfn;
> 	}
>
>-	/*
>-	 * Clear pageblock skip if there were failures recently and compaction
>-	 * is about to be retried after being deferred. kswapd does not do
>-	 * this reset as it'll reset the cached information when going to sleep.
>-	 */
>-	if (compaction_restarting(zone, cc->order) && !current_is_kswapd())
>-		__reset_isolation_suitable(zone);
>-
> 	migrate_prep_local();
>
> 	while ((ret = compact_finished(zone, cc)) == COMPACT_CONTINUE) {
>
>--
>To unsubscribe, send a message with 'unsubscribe linux-mm' in
>the body to majordomo@kvack.org.  For more info on Linux MM,
>see: http://www.linux-mm.org/ .
>Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>