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SubjectRe: [PATCH v2] perf: xgene: Add CPU hotplug support
Hi Hoan,

On Wed, Sep 19, 2018 at 06:44:30PM +0000, Hoan Tran wrote:
> This patch adds CPU hotplug support where the PMU migrates the context to
> another online CPU when its CPU is offline.
> It fixes the below issue where the user does offline the CPU which is assigned
> to this PMU.
> Assuming, CPU0 is assigned for this PMU. When the user does offline CPU0
> [root@(none) ~]# echo 0 > /sys/devices/system/cpu/cpu0/online
> This PMU does not work anymore and shows the below error.
> [root@(none) ~]# perf stat -a -e l3c0/cycle-count/,l3c0/write/ sleep 1
> Error:
> The sys_perf_event_open() syscall returned with 19 (No such device) for event (l3c0/cycle-count/).
> /bin/dmesg may provide additional information.
> No CONFIG_PERF_EVENTS=y kernel support configured?
> With this patch, when CPU0 is offline, PMU migrates to another online CPU and
> works on that CPU.
> Signed-off-by: Hoan Tran <>
> ---
> v2:
> * Remove the cpuhp instance when unregistering the PMU

Unfortunately, this has come through whitespae-damaged, with a
disclaimer in the footer.

Could you please resend with those two details fixed?


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