Re: [RFT][PATCH 1/3] PM: QoS: Introduce frequency QoS

From: Rafael J. Wysocki
Date: Wed Nov 20 2019 - 04:09:05 EST


On Wed, Nov 20, 2019 at 7:55 AM Doug Smythies <dsmythies@xxxxxxxxx> wrote:
>
> On 2019.11.19 14:14 Rafael J. Wysocki wrote:
> > On Tuesday, November 19, 2019 8:17:05 PM CET Rafael J. Wysocki wrote:
>
> ...
>
> >> However, I now also see that freq_qos_remove_request() doesn't clear
> >> the qos field in req which is should do, so freq_qos_add_request()
> >> will complain and fail if the object pointed to by req is passed to it
> >> again.
> >>
> >> I'll send a patch to test for this later today.
> >>
> >
> > The patch is appended. Please test it (on top of 5.4-rc8) and report back.
> >
> > ---
> > kernel/power/qos.c | 8 +++++++-
> > 1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > Index: linux-pm/kernel/power/qos.c
> > ===================================================================
> > --- linux-pm.orig/kernel/power/qos.c
> > +++ linux-pm/kernel/power/qos.c
> > @@ -814,6 +814,8 @@ EXPORT_SYMBOL_GPL(freq_qos_update_reques
> > */
> > int freq_qos_remove_request(struct freq_qos_request *req)
> > {
> > + int ret;
> > +
> > if (!req)
> > return -EINVAL;
> >
> > @@ -821,7 +823,11 @@ int freq_qos_remove_request(struct freq_
> > "%s() called for unknown object\n", __func__))
> > return -EINVAL;
> >
> > - return freq_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
> > + ret = freq_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
> > + req->qos = NULL;
> > + req->type = 0;
> > +
> > + return ret;
> > }
> > EXPORT_SYMBOL_GPL(freq_qos_remove_request);
>
> Yes the patch fixes the problem. Thanks.
>
> I tested several hundred times switching between
> passive and active modes with the intel_pstate driver,
> including with various CPUs disabled and re-enabled.

Thanks a lot!

Let me resend the patch with a changelog and tags.