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authorArnaldo Carvalho de Melo <acme@redhat.com>2019-07-08 13:06:57 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-07-08 13:06:57 -0300
commite3b22a65348ab54261a98b6bc90ecf8977ff8ebf (patch)
tree81c517d6f0e5585be7af5ffa1a4d4136b1f4a9c6 /Documentation/ABI/testing/sysfs-devices-system-cpu
parent05c78468a60f2fd961cd0a0c01c27f288bf81204 (diff)
parent552a031ba12a4236be107a5b082a399237758a5d (diff)
Merge remote-tracking branch 'tip/perf/core' into perf/urgent
To pick up fixes. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-devices-system-cpu')
-rw-r--r--Documentation/ABI/testing/sysfs-devices-system-cpu23
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 1528239f69b2..923fe2001472 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -538,3 +538,26 @@ Description: Intel Energy and Performance Bias Hint (EPB)
This attribute is present for all online CPUs supporting the
Intel EPB feature.
+
+What: /sys/devices/system/cpu/umwait_control
+ /sys/devices/system/cpu/umwait_control/enable_c02
+ /sys/devices/system/cpu/umwait_control/max_time
+Date: May 2019
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description: Umwait control
+
+ enable_c02: Read/write interface to control umwait C0.2 state
+ Read returns C0.2 state status:
+ 0: C0.2 is disabled
+ 1: C0.2 is enabled
+
+ Write 'y' or '1' or 'on' to enable C0.2 state.
+ Write 'n' or '0' or 'off' to disable C0.2 state.
+
+ The interface is case insensitive.
+
+ max_time: Read/write interface to control umwait maximum time
+ in TSC-quanta that the CPU can reside in either C0.1
+ 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.