Re: [PATCH v4 5/6] Documentation: Document sysfs interfaces purr, spurr, idle_purr, idle_spurr

Naveen N. Rao
2020-04-01T09:46:09Z

Gautham R. Shenoy wrote:
> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
>
> Add documentation for the following sysfs interfaces:
> /sys/devices/system/cpu/cpuX/purr
> /sys/devices/system/cpu/cpuX/spurr
> /sys/devices/system/cpu/cpuX/idle_purr
> /sys/devices/system/cpu/cpuX/idle_spurr
>
> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> ---
> Documentation/ABI/testing/sysfs-devices-system-cpu | 39 ++++++++++++++++++++++
> 1 file changed, 39 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
> index 2e0e3b4..bc07677 100644
> --- a/Documentation/ABI/testing/sysfs-devices-system-cpu
> +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
> @@ -580,3 +580,42 @@ Description: Secure Virtual Machine
> If 1, it means the system is using the Protected Execution
> Facility in POWER9 and newer processors. i.e., it is a Secure
> Virtual Machine.
> +
> +What: /sys/devices/system/cpu/cpuX/purr
> +Date: Apr 2005
> +Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
> +Description: PURR ticks for this CPU since the system boot.
> +
> + The Processor Utilization Resources Register (PURR) is
> + a 64-bit counter which provides an estimate of the
> + resources used by the CPU thread. The contents of this
> + register increases monotonically. This sysfs interface
> + exposes the number of PURR ticks for cpuX.
> +
> +What: /sys/devices/system/cpu/cpuX/spurr
> +Date: Dec 2006
> +Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
> +Description: SPURR ticks for this CPU since the system boot.
> +
> + The Scaled Processor Utilization Resources Register
> + (SPURR) is a 64-bit counter that provides a frequency
> + invariant estimate of the resources used by the CPU
> + thread. The contents of this register increases
> + monotonically. This sysfs interface exposes the number
> + of SPURR ticks for cpuX.
> +
> +What: /sys/devices/system/cpu/cpuX/idle_purr
> +Date: Mar 2020
> +Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
> +Description: PURR ticks for cpuX when it was idle.
> +
> + This sysfs interface exposes the number of PURR ticks
> + for cpuX when it was idle.
> +
> +What: /sys/devices/system/cpu/cpuX/idle_spurr
> +Date: Mar 2020
> +Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
> +Description: SPURR ticks for cpuX when it was idle.
> +
> + This sysfs interface exposes the number of SPURR ticks
> + for cpuX when it was idle.

Apart from the minor comment on patches 2 and 3, from the sysfs
interface standpoint, for patches 1 to 5:
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

- Naveen