Documentation: Document sysfs interfaces purr, spurr, idle_purr, idle_spurr

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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1586249263-14048-6-git-send-email-ego@linux.vnet.ibm.com
This commit is contained in:
Gautham R. Shenoy 2020-04-07 14:17:43 +05:30 коммит произвёл Michael Ellerman
Родитель 6909f179ca
Коммит bde752c3d6
1 изменённых файлов: 39 добавлений и 0 удалений

Просмотреть файл

@ -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: Apr 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: Apr 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.