Hi to all, In data martedì 27 ottobre 2020 17:42:19 CET, Mark Pearson ha scritto: > From: Hans de Goede <hdegoede@xxxxxxxxxx> > > On modern systems the platform performance, temperature, fan and other > hardware related characteristics are often dynamically configurable. The > profile is often automatically adjusted to the load by somei > automatic-mechanism (which may very well live outside the kernel). > > These auto platform-adjustment mechanisms often can be configured with > one of several 'platform-profiles', with either a bias towards low-power > consumption or towards performance (and higher power consumption and > thermals). > > Introduce a new platform_profile sysfs API which offers a generic API for > selecting the performance-profile of these automatic-mechanisms. > > Co-developed-by: Mark Pearson <markpearson@xxxxxxxxxx> > Signed-off-by: Mark Pearson <markpearson@xxxxxxxxxx> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > --- > Changes in V1: > - Moved from RFC to proposed patch > - Added cool profile as requested > - removed extra-profiles as no longer relevant > > .../ABI/testing/sysfs-platform_profile | 66 +++++++++++++++++++ > 1 file changed, 66 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-platform_profile > > diff --git a/Documentation/ABI/testing/sysfs-platform_profile > b/Documentation/ABI/testing/sysfs-platform_profile new file mode 100644 > index 000000000000..240bd3d7532b > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-platform_profile > @@ -0,0 +1,66 @@ > +Platform-profile selection (e.g. /sys/firmware/acpi/platform_profile) > + > +On modern systems the platform performance, temperature, fan and other > +hardware related characteristics are often dynamically configurable. The > +profile is often automatically adjusted to the load by some > +automatic-mechanism (which may very well live outside the kernel). > + > +These auto platform-adjustment mechanisms often can be configured with > +one of several 'platform-profiles', with either a bias towards low-power > +consumption or towards performance (and higher power consumption and > +thermals). > + > +The purpose of the platform_profile attribute is to offer a generic sysfs > +API for selecting the platform-profile of these automatic-mechanisms. > + > +Note that this API is only for selecting the platform-profile, it is > +NOT a goal of this API to allow monitoring the resulting performance > +characteristics. Monitoring performance is best done with device/vendor > +specific tools such as e.g. turbostat. > + > +Specifically when selecting a high-performance profile the actual achieved > +performance may be limited by various factors such as: the heat generated > +by other components, room temperature, free air flow at the bottom of a > +laptop, etc. It is explicitly NOT a goal of this API to let userspace know > +about any sub-optimal conditions which are impeding reaching the requested > +performance level. > + > +Since numbers are a rather meaningless way to describe platform-profiles > +this API uses strings to describe the various profiles. To make sure that > +userspace gets a consistent experience when using this API this API > +document defines a fixed set of profile-names. Drivers *must* map their > +internal profile representation/names onto this fixed set. > + > +If for some reason there is no good match when mapping then a new > profile-name +may be added. Drivers which wish to introduce new > profile-names must: +1. Have very good reasons to do so. > +2. Add the new profile-name to this document, so that future drivers which > also + have a similar problem can use the same name. > + > +What: /sys/firmware/acpi/platform_profile_choices > +Date: October 2020 > +Contact: Hans de Goede <hdegoede@xxxxxxxxxx> > +Description: > + Reading this file gives a space separated list of profiles > + supported for this device. > + > + Drivers must use the following standard profile-names: > + > + low-power: Emphasises low power consumption > + cool: Emphasises cooler operation > + quiet: Emphasises quieter operation > + balanced: Balance between low power consumption > + and performance > + performance: Emphasises performance (and may lead to > + higher temperatures and fan speeds) > + > + Userspace may expect drivers to offer at least several of these > + standard profile-names. > + > +What: /sys/firmware/acpi/platform_profile > +Date: October 2020 > +Contact: Hans de Goede <hdegoede@xxxxxxxxxx> > +Description: > + Reading this file gives the current selected profile for this > + device. Writing this file with one of the strings from > + available_profiles changes the profile to the new value. > -- > 2.28.0 >From my perspective now is perfect, thanks to all for the work. Regards Elia
