Re: [Qemu-devel] [PATCH 4/9] mm: compaction: Abort compaction loop if lock is contended or run too long

[Rafael Aquini]

On Fri, Sep 21, 2012 at 11:46:18AM +0100, Mel Gorman wrote:
> From: Shaohua Li <address@hidden>
> 
> Changelog since V2
> o Fix BUG_ON triggered due to pages left on cc.migratepages
> o Make compact_zone_order() require non-NULL arg `contended'
> 
> Changelog since V1
> o only abort the compaction if lock is contended or run too long
> o Rearranged the code by Andrea Arcangeli.
> 
> isolate_migratepages_range() might isolate no pages if for example when
> zone->lru_lock is contended and running asynchronous compaction. In this
> case, we should abort compaction, otherwise, compact_zone will run a
> useless loop and make zone->lru_lock is even contended.
> 
> address@hidden: Putback pages isolated for migration if aborting]
> address@hidden: compact_zone_order requires non-NULL arg contended]
> Signed-off-by: Andrea Arcangeli <address@hidden>
> Signed-off-by: Shaohua Li <address@hidden>
> Signed-off-by: Mel Gorman <address@hidden>
> Acked-by: Rik van Riel <address@hidden>
> ---

Acked-by: Rafael Aquini <address@hidden>