Re: [PATCH 6/7] mm: page allocator: Limit when direct reclaim isused when compaction is deferred

[Minchan Kim]

On Mon, Nov 21, 2011 at 06:36:47PM +0000, Mel Gorman wrote:
> If compaction is deferred, we enter direct reclaim to try reclaim the
> pages that way. For small high-orders, this has a reasonable chance
> of success. However, if the caller as specified __GFP_NO_KSWAPD to
> limit the disruption to the system, it makes more sense to fail the
> allocation rather than stall the caller in direct reclaim. This patch
> will skip direct reclaim if compaction is deferred and the caller
> specifies __GFP_NO_KSWAPD.
> 
> Async compaction only considers a subset of pages so it is possible for
> compaction to be deferred prematurely and not enter direct reclaim even
> in cases where it should. To compensate for this, this patch also defers
> compaction only if sync compaction failed.
> 
> Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Acked-by: Minchan Kim <minchan.kim@xxxxxxxxx>

It does make sense to me. 

-- 
Kind regards,
Minchan Kim
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/