Messages in this thread | | | Subject | Re: [tip: sched/core] x86, sched: Add support for frequency invariance | From | Chris Wilson <> | Date | Tue, 31 Mar 2020 19:33:50 +0100 |
| |
Quoting Giovanni Gherdovich (2020-03-31 19:11:25) > Hello Chris, > > thank you for catching this problem and sorry for the mess. > > Until your message I wasn't aware that CPU0 can be hotplugged, but now that I > check the feature is been there since v3.8 :/ > > The code assumes cpu0 is always there and I need to fix that. > > It seems your report comes from executing an automated test suite, can you > give me a link to the test sources and a hint on how to run it? I'd like to > reproduce locally so that I make sure I correctly address this problem.
https://gitlab.freedesktop.org/drm/igt-gpu-tools/
It's an i915 test (so expects i915 running and root access to your machine, with the intent of breaking your machine), but the cpu hotplugging could be extracted
https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/blob/master/tests/perf_pmu.c#L1153
since it's basically doing: i = 0 while :; do test -e /sys/devices/system/cpu/cpu$i/online || break
echo 0 > /sys/devices/system/cpu/cpu$i/online sleep .1 echo 1 > /sys/devices/system/cpu/cpu$i/online
i = $[[ $i + 1 ]] done dmesg
Possibly running that under perf stat to keep perf_event_open, or something else that hooks up the perf cpu hotplug callbacks.
Hope that helps, -Chris
| |