lkml.org 
[lkml]   [2014]   [May]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 07/17] mm: page_alloc: Take the ALLOC_NO_WATERMARK check out of the fast path
On 05/01/2014 04:44 AM, Mel Gorman wrote:
> ALLOC_NO_WATERMARK is set in a few cases. Always by kswapd, always for
> __GFP_MEMALLOC, sometimes for swap-over-nfs, tasks etc. Each of these cases
> are relatively rare events but the ALLOC_NO_WATERMARK check is an unlikely
> branch in the fast path. This patch moves the check out of the fast path
> and after it has been determined that the watermarks have not been met. This
> helps the common fast path at the cost of making the slow path slower and
> hitting kswapd with a performance cost. It's a reasonable tradeoff.
>
> Signed-off-by: Mel Gorman <mgorman@suse.de>
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>

Reviewed-by: Rik van Riel <riel@redhat.com>

--
All rights reversed


\
 
 \ /
  Last update: 2014-05-06 20:01    [W:0.296 / U:0.492 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site