Re: [PATCH] s390/pai: Handle CPU hotplug add for PAI PMU
| Newsgroups | org.kernel.vger.linux-s390 |
|---|---|
| Message-ID | <[email protected]> |
> The command 'perf stat -e pai_crypto/CRYPTO_ALL/ -- <command>
> crashes the kernel when CPUs are hotplug added during that run.
>
> Root cause is the allocation of struct pai_mapptr at first
> event initialization. The allocation is dynamic and the first
> event that has task context creates such a structure for
> each online CPU. This is not sufficient. CPUs may be offline
> during event creation and can be set online during the
> perf run time. For example commands
>
> # echo 0 > /sys/devices/system/cpu/cpu1/online
> # perf stat -e pai_crypto/CRYPTO_ALL/ -i -- stress-ng -t10s --matrix X
> # sleep 1
> # echo 1 > /sys/devices/system/cpu/cpu1/online
>
> [ ... ]
> possible CPUs, not just the ones currently online.
>
> Fixes: 92ea686840ac ("s390/pai_crypto: Enable per-task counting event")
> Cc: <[email protected]> # v6.11+
> Signed-off-by: Thomas Richter <[email protected]>
Sashiko has reviewed this patch and found no issues. It looks great!
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Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=1