[lkml]   [2011]   [Dec]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 09/11] mm: vmscan: When reclaiming for compaction, ensure there are sufficient free pages available
On 12/14/2011 10:41 AM, Mel Gorman wrote:
> In commit [e0887c19: vmscan: limit direct reclaim for higher order
> allocations], Rik noted that reclaim was too aggressive when THP was
> enabled. In his initial patch he used the number of free pages to
> decide if reclaim should abort for compaction. My feedback was that
> reclaim and compaction should be using the same logic when deciding if
> reclaim should be aborted.
> Unfortunately, this had the effect of reducing THP success rates when
> the workload included something like streaming reads that continually
> allocated pages. The window during which compaction could run and return
> a THP was too small.
> This patch combines Rik's two patches together. compaction_suitable()
> is still used to decide if reclaim should be aborted to allow
> compaction is used. However, it will also ensure that there is a
> reasonable buffer of free pages available. This improves upon the
> THP allocation success rates but bounds the number of pages that are
> freed for compaction.
> Signed-off-by: Mel Gorman<>

Reviewed-by: Rik van Riel<>

All rights reversed

 \ /
  Last update: 2011-12-16 05:39    [W:0.215 / U:0.856 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site