Re: [RFD] Remove the userspace governor and the cooling device set state sysfs entry

[Lukasz Luba]

On 10/1/21 11:30 AM, Daniel Lezcano wrote:
> Hi Lukasz,
>
> On 30/09/2021 12:10, Lukasz Luba wrote:
> > Hi Daniel,
> >
> > On 9/22/21 10:59 AM, Daniel Lezcano wrote:
> > > Hi,
> > >
> > > the userspace governor is sending temperature when polling is active and
> > > trip point crossed events. Nothing else.
> > >
> > > In the other side, the cooling device have their cooling device
> > > set_cur_state read-writable all the time.
> > >
> > > The thermal framework is wrongly used by userspace as a power capping
> > > framework by acting on the cooling device opaque state. This one then
> > > competes with the in-kernel governor decision.
> > >
> > > As the new netlink thermal notification is able to provide the same
> > > information than the userspace governor.
> > >
> > > I propose to remove the userspace governor and the cur_state entry in
> > > the sysfs exported file.
> > >
> > > The DTPM framework is the right framework to do power capping and
> > > moreover it deals with the aggregation via the dev pm qos.
> > >
> > > Does it make sense ?
> >
> > It sounds that we should be OK with the information from netlink.
> > I don't see objections. We can also extend the netlink packet when
> > needed. I'm fine with removing the user-space governor.
>
> thank you for your answer. I'll propose a patch with a warn when the
> userspace governor is registered in order to let know people the
> governor is deprecated.
>
> Probably, it would make sense to emit a warning also when the cooling
> device state is set from userspace.
>
> For the next release, we should be able to drop the userspace governor
> and make the cooling device state read-only.
>
> Does it make sense ?

Yes, it makes sense.