lkml.org 
[lkml]   [2016]   [May]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: sched: tweak select_idle_sibling to look for idle threads
From
Date
On Sun, 2016-05-01 at 10:53 +0200, Peter Zijlstra wrote:
> On Sun, May 01, 2016 at 09:12:33AM +0200, Mike Galbraith wrote:
> > On Sat, 2016-04-30 at 14:47 +0200, Peter Zijlstra wrote:
>
> > > Can you guys have a play with this; I think one and two node tbench are
> > > good, but I seem to be getting significant run to run variance on that,
> > > so maybe I'm not doing it right.
> >
> > Nah, tbench is just variance prone. It got dinged up at clients=cores
> > on my desktop box, on 4 sockets the high end got seriously dinged up.
>
> Ouch, yeah, big hurt. Lets try that again... :-)

Yeah, box could use a little bandaid and a hug :)

Playing with Chris' benchmark, seems the biggest problem is that we
don't buddy up waker of many and it's wakees in a node.. ie the wake
wide thing isn't necessarily our friend when there are multiple wakers
of many. If I run an instance per node with one mother of all work in
autobench mode, it works exactly as you'd expect, game over is when
wakees = socket size. It never get's near that point if I let things
wander, it beats itself up well before we get there.

-Mike

\
 
 \ /
  Last update: 2016-05-01 11:41    [W:0.095 / U:0.280 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site