Messages in this thread Patch in this message |  | | Date | Mon, 19 Dec 2022 16:35:11 -0600 | Subject | Re: [PATCH v8 13/13] Documentation: amd-pstate: introduce new global sysfs attributes | From | "Limonciello, Mario" <> |
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On 12/19/2022 00:40, Perry Yuan wrote: > The new amd-pstate driver support to switch the driver working mode and
Words like "new" don't age well.
> use can switch the driver mode within the sysfs attributes in the below > path and check current mode
Perhaps "The amd-pstate driver supports switching working modes at runtime. Users can view and change modes by interacting with the "status" sysfs attribute.
> > $ cd /sys/devices/system/cpu/amd-pstate >
No need to change directories; you're demonstrating below using full paths.
> check driver mode: > $ cat /sys/devices/system/cpu/amd-pstate/status > > switch mode: > $ sudo bash -c "echo passive > /sys/devices/system/cpu/amd-pstate/status" > or > $ sudo bash -c "echo active > /sys/devices/system/cpu/amd-pstate/status"
Another way you could suggest this:
# echo "passive" | sudo tee /sys/devices/system/cpu/amd-pstate/status or # echo "active" | sudo tee /sys/devices/system/cpu/amd-pstate/status
I don't feel strongly which way to suggest though.
> > Signed-off-by: Perry Yuan <perry.yuan@amd.com> > --- > Documentation/admin-guide/pm/amd-pstate.rst | 28 +++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst > index 62744dae3c5f..f3a8f8a66783 100644 > --- a/Documentation/admin-guide/pm/amd-pstate.rst > +++ b/Documentation/admin-guide/pm/amd-pstate.rst > @@ -339,6 +339,34 @@ processor must provide at least nominal performance requested and go higher if c > operating conditions allow. > > > +User Space Interface in ``sysfs`` > +================================= > + > +Global Attributes > +----------------- > + > +``amd-pstate`` exposes several global attributes (files) in ``sysfs`` to > +control its functionality at the system level. They are located in the > +``/sys/devices/system/cpu/amd-pstate/`` directory and affect all CPUs. > + > +``status`` > + Operation mode of the driver: "active", "passive" or "off". > + > + "active" > + The driver is functional and in the ``active mode`` > + > + "passive" > + The driver is functional and in the ``passive mode`` > + > + "off" > + The driver is unregistered and not functional now. > + > + This attribute can be written to in order to change the driver's > + operation mode or to unregister it. The string written to it must be > + one of the possible values of it and, if successful, the write will
I think this is implied that you wrote a possible value and if it returns success something happens. That's how all sysfs files work and it's needlessly wordy.
> + cause the driver to switch over to the operation mode represented by > + that string - or to be unregistered in the "off" case. Considering the implication of my above comment I think you can reword this as:
"Writing one of these values to the sysfs file will cause the driver to..."
> + > ``cpupower`` tool support for ``amd-pstate`` > =============================================== >
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