On Tue, Feb 6, 2018 at 8:19 PM, Aishwarya Pant <[email protected]> wrote: > Update cpuidle documentation using git logs and existing documentation > in Documentation/cpuidle/sysfs.txt. This might be useful for scripting > and tracking changes in the ABI. > > Signed-off-by: Aishwarya Pant <[email protected]> > --- > Changes in v4: > - Fix patch formatting > v3: > - Fix subject line > v2: > - Merge cpuidle_sysfs_switch attributes' description with the previous > entry. > > Documentation/ABI/testing/sysfs-devices-system-cpu | 77 > +++++++++++++++++++++- > 1 file changed, 75 insertions(+), 2 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu > b/Documentation/ABI/testing/sysfs-devices-system-cpu > index bfd29bc8d37a..e9ee67f80933 100644 > --- a/Documentation/ABI/testing/sysfs-devices-system-cpu > +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu > @@ -108,6 +108,8 @@ Description: CPU topology files that describe a > logical CPU's relationship > > What: /sys/devices/system/cpu/cpuidle/current_driver > /sys/devices/system/cpu/cpuidle/current_governer_ro > + /sys/devices/system/cpu/cpuidle/available_governors > + /sys/devices/system/cpu/cpuidle/current_governor > Date: September 2007 > Contact: Linux kernel mailing list <[email protected]> > Description: Discover cpuidle policy and mechanism > @@ -119,13 +121,84 @@ Description: Discover cpuidle policy and mechanism > Idle policy (governor) is differentiated from idle mechanism > (driver) > > - current_driver: displays current idle mechanism > + current_driver: (RO) displays current idle mechanism > > - current_governor_ro: displays current idle policy > + current_governor_ro: (RO) displays current idle policy > + > + With the cpuidle_sysfs_switch boot option enabled (meant for > + developer testing), the following three attributes are visible > + instead: > + > + current_driver: same as described above > + > + available_governors: (RO) displays a space separated list of > + available governors > + > + 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. > > > +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/name > + /sys/devices/system/cpu/cpuX/cpuidle/stateN/latency > + /sys/devices/system/cpu/cpuX/cpuidle/stateN/power > + /sys/devices/system/cpu/cpuX/cpuidle/stateN/time > + /sys/devices/system/cpu/cpuX/cpuidle/stateN/usage > +Date: September 2007 > +KernelVersion: v2.6.24 > +Contact: Linux kernel mailing list <[email protected]>
Please replace "Linux kernel mailing list <[email protected]>" with "Linux power management list <[email protected]>" here and below. > +Description: > + The directory /sys/devices/system/cpu/cpuX/cpuidle contains > per > + logical CPU specific cpuidle information for each online cpu > X. > + The processor idle states which are available for use have the > + following attributes: > + > + name: (RO) Name of the idle state (string). > + > + latency: (RO) The latency to exit out of this idle state (in > + microseconds). > + > + power: (RO) The power consumed while in this idle state (in > + milliwatts). > + > + time: (RO) The total time spent in this idle state (in > microseconds). > + > + usage: (RO) Number of times this state was entered (a count). > + > + > +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/desc > +Date: February 2008 > +KernelVersion: v2.6.25 > +Contact: Linux kernel mailing list <[email protected]> > +Description: > + (RO) A small description about the idle state (string). > + > + > +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/disable > +Date: March 2012 > +KernelVersion: v3.10 > +Contact: Linux kernel mailing list <[email protected]> > +Description: > + (RW) Option to disable this idle state (bool). 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, but the disable > variable > + does not reflect it. Likewise, if one enables a deep state > but a > + lighter state still is disabled, then this has no effect. > + > + > +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/residency > +Date: March 2014 > +KernelVersion: v3.15 > +Contact: Linux kernel mailing list <[email protected]> > +Description: > + (RO) Display the target residency i.e. the minimum amount of > + time (in microseconds) this cpu should spend in this idle > state > + to make the transition worth the effort. > + > + > What: /sys/devices/system/cpu/cpu#/cpufreq/* > Date: pre-git history > Contact: [email protected] > -- > 2.16.1 >
