Re: [PATCH 01/10] mm, compaction: do not recheck suitable_migration_target under lock

2014-06-10 Thread Zhang Yanfei
On 06/09/2014 05:26 PM, Vlastimil Babka wrote: > isolate_freepages_block() rechecks if the pageblock is suitable to be a target > for migration after it has taken the zone->lock. However, the check has been > optimized to occur only once per pageblock, and compact_checklock_irqsave() > might be dro

Re: [PATCH 01/10] mm, compaction: do not recheck suitable_migration_target under lock

2014-06-10 Thread Minchan Kim
On Mon, Jun 09, 2014 at 11:26:13AM +0200, Vlastimil Babka wrote: > isolate_freepages_block() rechecks if the pageblock is suitable to be a target > for migration after it has taken the zone->lock. However, the check has been > optimized to occur only once per pageblock, and compact_checklock_irqsav

Re: [PATCH 01/10] mm, compaction: do not recheck suitable_migration_target under lock

2014-06-09 Thread David Rientjes
On Mon, 9 Jun 2014, Vlastimil Babka wrote: > isolate_freepages_block() rechecks if the pageblock is suitable to be a target > for migration after it has taken the zone->lock. However, the check has been > optimized to occur only once per pageblock, and compact_checklock_irqsave() > might be droppi

[PATCH 01/10] mm, compaction: do not recheck suitable_migration_target under lock

2014-06-09 Thread Vlastimil Babka
isolate_freepages_block() rechecks if the pageblock is suitable to be a target for migration after it has taken the zone->lock. However, the check has been optimized to occur only once per pageblock, and compact_checklock_irqsave() might be dropping and reacquiring lock, which means somebody else m