From 5094d271715a5bd0f7f4adb38d825ce6903eb6eb Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Sat, 16 Nov 2013 14:39:21 +0100 Subject: [PATCH 1/2] tools: cpupower: Add cpupower-idle-set(1) manpage The cpupower idle-set subcommand was introduce recently. This patch provides the missing manpage. If cpupower is properly installed it will show up automatically (similar to git), when invoking: cpupower help idle-set or cpupower idle-set --help Some parts have been taken over and adjusted from git commit 62d6ae880e3e76098 documentation submitted by Carsten Emde. Signed-off-by: Thomas Renninger Signed-off-by: Rafael J. Wysocki --- tools/power/cpupower/man/cpupower-idle-info.1 | 3 +- tools/power/cpupower/man/cpupower-idle-set.1 | 71 +++++++++++++++++++ 2 files changed, 73 insertions(+), 1 deletion(-) create mode 100644 tools/power/cpupower/man/cpupower-idle-set.1 diff --git a/tools/power/cpupower/man/cpupower-idle-info.1 b/tools/power/cpupower/man/cpupower-idle-info.1 index 4178effd9e99..7b3646adb92f 100644 --- a/tools/power/cpupower/man/cpupower-idle-info.1 +++ b/tools/power/cpupower/man/cpupower-idle-info.1 @@ -87,4 +87,5 @@ Thomas Renninger .fi .SH "SEE ALSO" .LP -cpupower(1), cpupower\-monitor(1), cpupower\-info(1), cpupower\-set(1) +cpupower(1), cpupower\-monitor(1), cpupower\-info(1), cpupower\-set(1), +cpupower\-idle\-set(1) diff --git a/tools/power/cpupower/man/cpupower-idle-set.1 b/tools/power/cpupower/man/cpupower-idle-set.1 new file mode 100644 index 000000000000..6b1607272a5b --- /dev/null +++ b/tools/power/cpupower/man/cpupower-idle-set.1 @@ -0,0 +1,71 @@ +.TH "CPUPOWER-IDLE-SET" "1" "0.1" "" "cpupower Manual" +.SH "NAME" +.LP +cpupower idle\-set \- Utility to set cpu idle state specific kernel options +.SH "SYNTAX" +.LP +cpupower [ \-c cpulist ] idle\-info [\fIoptions\fP] +.SH "DESCRIPTION" +.LP +The cpupower idle\-set subcommand allows to set cpu idle, also called cpu +sleep state, specific options offered by the kernel. One example is disabling +sleep states. This can be handy for power vs performance tuning. +.SH "OPTIONS" +.LP +.TP +\fB\-d\fR \fB\-\-disable\fR +Disable a specific processor sleep state. +.TP +\fB\-e\fR \fB\-\-enable\fR +Enable a specific processor sleep state. + +.SH "REMARKS" +.LP +Cpuidle Governors Policy on Disabling Sleep States + +.RS 4 +Depending on the used cpuidle governor, implementing the kernel policy +how to choose sleep states, subsequent sleep states on this core, might get +disabled as well. + +There are two cpuidle governors ladder and menu. While the ladder +governor is always available, if CONFIG_CPU_IDLE is selected, the +menu governor additionally requires CONFIG_NO_HZ. + +The behavior and the effect of the disable variable depends on the +implementation of a particular governor. In the ladder governor, for +example, it is not coherent, i.e. if one is disabling a light state, +then all deeper states are disabled as well. Likewise, if one enables a +deep state but a lighter state still is disabled, then this has no effect. +.RE +.LP +Disabling the Lightest Sleep State may not have any Affect + +.RS 4 +If criteria are not met to enter deeper sleep states and the lightest sleep +state is chosen when idle, the kernel may still enter this sleep state, +irrespective of whether it is disabled or not. This is also reflected in +the usage count of the disabled sleep state when using the cpupower idle-info +command. +.RE +.LP +Selecting specific CPU Cores + +.RS 4 +By default processor sleep states of all CPU cores are set. Please refer +to the cpupower(1) manpage in the \-\-cpu option section how to disable +C-states of specific cores. +.RE +.SH "FILES" +.nf +\fI/sys/devices/system/cpu/cpu*/cpuidle/state*\fP +\fI/sys/devices/system/cpu/cpuidle/*\fP +.fi +.SH "AUTHORS" +.nf +Thomas Renninger +.fi +.SH "SEE ALSO" +.LP +cpupower(1), cpupower\-monitor(1), cpupower\-info(1), cpupower\-set(1), +cpupower\-idle\-info(1) From f4a5d17efec95ee74113df62943494a2197c8bae Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Sat, 16 Nov 2013 14:39:22 +0100 Subject: [PATCH 2/2] tools: cpupower: fix wrong err msg not supported vs not available idlestates in sysfs are counted from 0. This fixes a wrong error message. Current behavior on a machine with 4 sleep states is: cpupower idle-set -e 4 Idlestate 4 enabled on CPU 0 -----Wrong--------------------- cpupower idle-set -e 5 Idlestate enabling not supported by kernel -----Must and now will be ----- cpupower idle-set -e 5 Idlestate 6 not available on CPU 0 ------------------------------- cpupower idle-set -e 6 Idlestate 6 not available on CPU 0 Signed-off-by: Thomas Renninger Signed-off-by: Rafael J. Wysocki --- tools/power/cpupower/utils/helpers/sysfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/power/cpupower/utils/helpers/sysfs.c b/tools/power/cpupower/utils/helpers/sysfs.c index 5cdc600e8152..851c7a16ca49 100644 --- a/tools/power/cpupower/utils/helpers/sysfs.c +++ b/tools/power/cpupower/utils/helpers/sysfs.c @@ -278,7 +278,7 @@ static char *sysfs_idlestate_get_one_string(unsigned int cpu, int sysfs_is_idlestate_disabled(unsigned int cpu, unsigned int idlestate) { - if (sysfs_get_idlestate_count(cpu) < idlestate) + if (sysfs_get_idlestate_count(cpu) <= idlestate) return -1; if (!sysfs_idlestate_file_exists(cpu, idlestate, @@ -303,7 +303,7 @@ int sysfs_idlestate_disable(unsigned int cpu, char value[SYSFS_PATH_MAX]; int bytes_written; - if (sysfs_get_idlestate_count(cpu) < idlestate) + if (sysfs_get_idlestate_count(cpu) <= idlestate) return -1; if (!sysfs_idlestate_file_exists(cpu, idlestate,