From bde752c3d6dbe9f6ca346560198e66bc3d7d7238 Mon Sep 17 00:00:00 2001
From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
Date: Tue, 7 Apr 2020 14:17:43 +0530
Subject: [PATCH] Documentation: Document sysfs interfaces purr, spurr,
idle_purr, idle_spurr
References: PED-3947 bsc#1210544 ltc#202303
Patch-mainline: v5.8-rc1
Git-commit: bde752c3d6dbe9f6ca346560198e66bc3d7d7238
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
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
.../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
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -439,3 +439,42 @@ Description: Umwait control
or C0.2 state. The time is an unsigned 32-bit number.
Note that a value of zero means there is no limit.
Low order two bits must be zero.
+
+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.