Re: [tip:sched/hrtick] [hrtimer] 2889243848: stress-ng.timermix.ops_per_sec 30.1% regression

Peter Zijlstra <[email protected]> Tue, 10 Mar 2026 19:50:06 +0100
Newsgroups dev.linux.lists.oe-lkp,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
On Tue, Mar 10, 2026 at 07:16:51PM +0100, Peter Zijlstra wrote:
> On Tue, Mar 10, 2026 at 01:11:09PM -0400, Joe Talbott wrote:
> 
> > It looks like it can be found here:
> > https://download.01.org/0day-ci/archive/20260310/[email protected]/repro-script
> > 
> > stress-ng --timeout 60 --times --verify --metrics --no-rand-seed --timermix 64
> 
> Thanks, that does indeed work and show the regression.
> 
> Lets see if I can spot the fail...

It looks like that benchmark manages to trip significant nr_hangs, and
yes, I made those more expensive because those were not expected to
actually happen at any sane rate.

Lets see if we can cure that without making a giant mess of things.