lkml.org 
[lkml]   [2016]   [Feb]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 07/27] mm, vmscan: Have kswapd only scan based on the highest requested zone
On Tue, Feb 23, 2016 at 03:04:30PM +0000, Mel Gorman wrote:
> kswapd checks all eligible zones to see if they need balancing even if it was
> woken for a lower zone. This made sense when we reclaimed on a per-zone basis
> because we wanted to shrink zones fairly so avoid age-inversion problems.
> Ideally this is completely unnecessary when reclaiming on a per-node basis.
> In theory, there may still be anomalies when all requests are for lower
> zones and very old pages are preserved in higher zones but this should be
> the exceptional case.
>
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

As I mentioned in the other subthread, this should probably be fine,
although it would be good, generally, to have some sort of statistics
on how much of the age-distorting reclaim is happening, and then maybe
mention its existence in the changelog of this patch. Just an idea.

\
 
 \ /
  Last update: 2016-02-26 00:01    [W:0.260 / U:1.320 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site