Re: Abysmal scheduler performance in Linus' tree?

From: Mike Galbraith
Date: Thu Sep 07 2017 - 02:16:17 EST


On Wed, 2017-09-06 at 18:14 +0200, Peter Zijlstra wrote:
> On Wed, Sep 06, 2017 at 11:03:33AM +0200, Peter Zijlstra wrote:
> > On Wed, Sep 06, 2017 at 01:59:14AM -0700, Andy Lutomirski wrote:
> > > > Any specifics on your setup?
> > >
> > > On further fiddling, I only see this after a suspend and resume cycle.
> >
> > Ah, ok. That's not something I otherwise test. Lets see if I can force
> > this brick of mine through a suspend-resume cycle :-)
>
> I'd be suspicious of these here commits:
>
> 77d1dfda0e79 ("sched/topology, cpuset: Avoid spurious/wrong domain rebuilds")

Seems to be that one. ÂAfter suspend/resume, cpu7 (i4790+SMT) is online
with NULL domain. Âoffline/online it, it grows proper domains.

-Mike

(on vacation, about to go explore that unfamiliar 'outside' place) Â