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SubjectRe: [PATCH 2/3] powerpc/sysfs: Show idle_purr and idle_spurr for every CPU
Christophe Leroy wrote:
> Le 27/11/2019 à 13:01, Gautham R. Shenoy a écrit :
>> From: "Gautham R. Shenoy" <>
>> On Pseries LPARs, to calculate utilization, we need to know the
>> [S]PURR ticks when the CPUs were busy or idle.
>> The total PURR and SPURR ticks are already exposed via the per-cpu
>> sysfs files /sys/devices/system/cpu/cpuX/purr and
>> /sys/devices/system/cpu/cpuX/spurr.
>> This patch adds support for exposing the idle PURR and SPURR ticks via
>> /sys/devices/system/cpu/cpuX/idle_purr and
>> /sys/devices/system/cpu/cpuX/idle_spurr.
> Might be a candid question, but I see in arch/powerpc/kernel/time.c that
> PURR/SPURR are already taken into account by the kernel to calculate
> utilisation when CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is selected.
> As far as I understand, you are wanting to expose this to userland to
> redo the calculation there. What is wrong with the values reported by
> the kernel ?

As you point out, it is only done with
which happens to be the distro default nowadays.

- Naveen

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