diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-devices-system-cpu')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 1528239f69b2..d404603c6b52 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -137,7 +137,8 @@ Description: Discover cpuidle policy and mechanism current_governor: (RW) displays current idle policy. Users can switch the governor at runtime by writing to this file. - See files in Documentation/cpuidle/ for more information. + See Documentation/admin-guide/pm/cpuidle.rst and + Documentation/driver-api/pm/cpuidle.rst for more information. What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/name @@ -538,3 +539,26 @@ 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. |