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

Joe Talbott <[email protected]> Tue, 10 Mar 2026 13:11:09 -0400
Newsgroups dev.linux.lists.oe-lkp,org.kernel.vger.linux-kernel
Message-ID <CAL7gdfeGFgppkRH5=pWfx7KCx78xsUPG_-aRsP3zqw+yLKJQ_A@mail.gmail.com>
On Tue, Mar 10, 2026 at 11:58 AM Peter Zijlstra <[email protected]> wrote:
>
> On Tue, Mar 10, 2026 at 10:46:16PM +0800, kernel test robot wrote:
> >
> >
> > Hello,
> >
> > kernel test robot noticed a 30.1% regression of stress-ng.timermix.ops_per_sec on:
> >
> >
> > commit: 2889243848560b6b0211aba401d2fc122070ba2f ("hrtimer: Re-arrange hrtimer_interrupt()")
> > https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git sched/hrtick
> >
> >
> > testcase: stress-ng
> > config: x86_64-rhel-9.4
> > compiler: gcc-14
> > test machine: 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory
> > parameters:
> >
> >       nr_threads: 100%
> >       testtime: 60s
> >       test: timermix
> >       cpufreq_governor: performance
> >
> >
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <[email protected]>
> > | Closes: https://lore.kernel.org/oe-lkp/[email protected]
> >
> >
> > Details are as below:
> > -------------------------------------------------------------------------------------------------->
> >
> >
> > The kernel config and materials to reproduce are available at:
> > https://download.01.org/0day-ci/archive/20260310/[email protected]
>
> As per always, I find it incredibly hard to deduce how the test is
> actually ran.
>
> I suppose this is:  stress-ng --timermix ....
> but what arguments exactly?
>

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

Joe