| Message ID | 1423517653-11359-13-git-send-email-edubezval@gmail.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
Hi Eduardo, On Mon, Feb 09, 2015 at 09:34:13PM +0000, Eduardo Valentin wrote: > In this patch we add a chapter in the thermal docbook to > describe the existing governors. The chapter contains > one section per governor. > > Each governor description includes the respective code documentation. > Each governor section contains a description of the governor > logic. > > Signed-off-by: Eduardo Valentin <edubezval@gmail.com> > --- > Documentation/DocBook/thermal.tmpl | 67 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 67 insertions(+) > > diff --git a/Documentation/DocBook/thermal.tmpl b/Documentation/DocBook/thermal.tmpl > index d6ebbea..cf1a198 100644 > --- a/Documentation/DocBook/thermal.tmpl > +++ b/Documentation/DocBook/thermal.tmpl > @@ -212,6 +212,73 @@ > </glossary> > </sect1> > </chapter> > + > + <chapter id="governors"> > + <title>Thermal Governors</title> > + <para> > + </para> > + > + <sect1 id="step_wise"> > + <title>step_wise Thermal Governor</title> > + <para>Step Wise uses the trend of the thermal zone to > + throttle. If the thermal zone is 'heating up' this > + throttles all the cooling devices associated with the > + zone and its particular trip point, by one step. If the > + zone is 'cooling down' it brings back the performance > + of the devices by one step. > + </para> > +!Idrivers/thermal/step_wise.c > +!Pdrivers/thermal/step_wise.c Algorithm > + </sect1> > + <sect1 id="fair_share"> > + <title>fair_share Thermal Governor</title> > + <para>Fair Share Governor uses three parameters to > + calculate the new throttle state of the cooling devices > + associated with the given zone. Parameters used for > + Throttling: > + </para> > + <itemizedlist mark='opencircle'> > + <listitem>P1. max_state: Maximum throttle state > + exposed by the cooling device.</listitem> > + <listitem>P2. weight[i]/100:</listitem> > + <listitem>How 'effective' the 'i'th device is, > + in cooling the given zone.</listitem> > + <listitem>P3. > + cur_trip_level/max_no_of_trips:</listitem> > + </itemizedlist> > + <para>This describes the extent to which the devices > + should be throttled. We do not want to throttle too > + much when we trip a lower temperature, whereas the > + throttling is at full swing if we trip critical levels. > + Heavily assumes the trip points are in ascending order > + new_state of cooling device = P3 * P2 * P1. > + </para> This seems to be heavily based on the kerneldoc in fair_share.c . Wouldn't it be better to do a similar trick to what you did in step_wise? That is, move that kerneldoc into an "Algorithm" entry and include it here. That way we avoid the duplication of the documentation. Cheers, Javi > +!Idrivers/thermal/fair_share.c > + </sect1> > + <sect1 id="bang_bang"> > + <title>bang_bang Thermal Governor</title> > + <para>The Bang Bang Governor has a two point regulation > + logic, deliver cooling state depending on the previous > + state shown in this diagram: </para> > + <para>If the fan is not running and temperature exceeds > + trip_temp, the fan gets turned on. In case the fan is > + running, temperature must fall below (trip_temp - hyst) > + so that the fan gets turned off again. > + </para> > +!Idrivers/thermal/gov_bang_bang.c > + </sect1> > + <sect1 id="user_space"> > + <title>user_space Thermal Governor</title> > + <para> The User Space governor is outside the Kernel. > + The Thermal Framework hands off the entire control to > + userland if the User Space governor is assigned to a > + thermal zone. A KOBJ_CHANGE UEvent notification is sent > + to userland whenever a governor needs to take an > + action. > + </para> > +!Idrivers/thermal/user_space.c > + </sect1> > + </chapter> > <chapter id="api"> > <title>Thermal Device Driver Writer API reference</title> > <para> This Chapter contains an API reference for Thermal driver writers. > -- > 2.1.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/DocBook/thermal.tmpl b/Documentation/DocBook/thermal.tmpl index d6ebbea..cf1a198 100644 --- a/Documentation/DocBook/thermal.tmpl +++ b/Documentation/DocBook/thermal.tmpl @@ -212,6 +212,73 @@ </glossary> </sect1> </chapter> + + <chapter id="governors"> + <title>Thermal Governors</title> + <para> + </para> + + <sect1 id="step_wise"> + <title>step_wise Thermal Governor</title> + <para>Step Wise uses the trend of the thermal zone to + throttle. If the thermal zone is 'heating up' this + throttles all the cooling devices associated with the + zone and its particular trip point, by one step. If the + zone is 'cooling down' it brings back the performance + of the devices by one step. + </para> +!Idrivers/thermal/step_wise.c +!Pdrivers/thermal/step_wise.c Algorithm + </sect1> + <sect1 id="fair_share"> + <title>fair_share Thermal Governor</title> + <para>Fair Share Governor uses three parameters to + calculate the new throttle state of the cooling devices + associated with the given zone. Parameters used for + Throttling: + </para> + <itemizedlist mark='opencircle'> + <listitem>P1. max_state: Maximum throttle state + exposed by the cooling device.</listitem> + <listitem>P2. weight[i]/100:</listitem> + <listitem>How 'effective' the 'i'th device is, + in cooling the given zone.</listitem> + <listitem>P3. + cur_trip_level/max_no_of_trips:</listitem> + </itemizedlist> + <para>This describes the extent to which the devices + should be throttled. We do not want to throttle too + much when we trip a lower temperature, whereas the + throttling is at full swing if we trip critical levels. + Heavily assumes the trip points are in ascending order + new_state of cooling device = P3 * P2 * P1. + </para> +!Idrivers/thermal/fair_share.c + </sect1> + <sect1 id="bang_bang"> + <title>bang_bang Thermal Governor</title> + <para>The Bang Bang Governor has a two point regulation + logic, deliver cooling state depending on the previous + state shown in this diagram: </para> + <para>If the fan is not running and temperature exceeds + trip_temp, the fan gets turned on. In case the fan is + running, temperature must fall below (trip_temp - hyst) + so that the fan gets turned off again. + </para> +!Idrivers/thermal/gov_bang_bang.c + </sect1> + <sect1 id="user_space"> + <title>user_space Thermal Governor</title> + <para> The User Space governor is outside the Kernel. + The Thermal Framework hands off the entire control to + userland if the User Space governor is assigned to a + thermal zone. A KOBJ_CHANGE UEvent notification is sent + to userland whenever a governor needs to take an + action. + </para> +!Idrivers/thermal/user_space.c + </sect1> + </chapter> <chapter id="api"> <title>Thermal Device Driver Writer API reference</title> <para> This Chapter contains an API reference for Thermal driver writers.
In this patch we add a chapter in the thermal docbook to describe the existing governors. The chapter contains one section per governor. Each governor description includes the respective code documentation. Each governor section contains a description of the governor logic. Signed-off-by: Eduardo Valentin <edubezval@gmail.com> --- Documentation/DocBook/thermal.tmpl | 67 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+)