Hi Kurt, On Fri, 5 Jun 2020 at 16:19, Vladimir Oltean <olteanv@xxxxxxxxx> wrote: > > Hi Kurt, > > On Fri, 5 Jun 2020 at 15:57, Kurt Kanzenbach > <kurt.kanzenbach@xxxxxxxxxxxxx> wrote: > > > > Hi Vladimir, > > > > On Fri Jun 05 2020, Vladimir Oltean wrote: > > > Hi, > > > > > > I was testing stress-ng on an ARM64 box and I found that it can be killed instantaneously with a --hrtimers 1 test: > > > https://github.com/ColinIanKing/stress-ng/blob/master/stress-hrtimers.c > > > The console shell locks up immediately after starting the process, and I get this rcu_preempt splat after 21 seconds, > > > letting me know that the grace-periods kernel thread could not run: > > > > interesting. Just tested this on an ARM64 box with v5.6-rt and the > > stress-ng hrtimer test works fine. No lockups, cyclictest results are > > looking good. So maybe this is v5.7 related. > > > > Thanks, > > Kurt > > This is not actually v5.7 related. I could also reproduce it on a > downstream 5.4 kernel which is how I originally saw it. > > Thanks, > -Vladimir Just out of curiosity, what and how many CPU cores does your ARM64 box have, and what frequency are you running them at? Mine is a dual-core A72 machine running at 1500 MHz. Thanks, -Vladimir
