Re: [PATCH 3/3 v6] s390/pai: Support CPU hotplug for PMU PAI
| 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 missing allocation of per-CPU data structures > for that new CPU. 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 cycles -i -- stress-ng -t10s --matrix X > # sleep 1 > # echo 1 > /sys/devices/system/cpu/cpu1/online > > [ ... ] > > #Cc: [email protected] # v6.19 > Fixes: 582cc1b28e8c ("s390/pai_ext: Enable per-task and system-wide sampling event") > Fixes: 9f66572f2889 ("s390/pai_crypto: Enable per-task and system-wide sampling event") > Signed-off-by: Thomas Richter <[email protected]> Sashiko has reviewed this patch and found no issues. It looks great! -- Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=3