Re: [Bug #12152] Huge wakeups number from i1915

Arjan van de Ven
2008-12-07T23:12:03Z

On Sun, 7 Dec 2008 23:52:06 +0100
"Rafael J. Wysocki" <rjw-KKrjLPT3xs0@public.gmane.org> wrote:

> On Sunday, 7 of December 2008, Arjan van de Ven wrote:
> > On Sun, 7 Dec 2008 21:32:54 +0100 (CET)
> > "Rafael J. Wysocki" <rjw-KKrjLPT3xs0@public.gmane.org> wrote:
> >
> > > This message has been generated automatically as a part of a
> > > report of recent regressions.
> > >
> > > The following bug entry is on the current list of known
> > > regressions from 2.6.27. Please verify if it still should be
> > > listed and let me know (either way).
> > >
> > >
> > > Bug-Entry :
> > > http://bugzilla.kernel.org/show_bug.cgi?id=12152
> > > Subject : Huge wakeups number from i1915
> > > Submitter : Yves-Alexis Perez <corsac-8fiUuRrzOP0dnm+yROfE0A@public.gmane.org>
> > > Date : 2008-12-02 16:48 (6 days old)
> > > References :
> > > http://marc.info/?l=linux-acpi&m=122823656702994&w=4
> > >
> >
> > at least in some of the cases where this has been seen the cause is
> > the following:
> > The i915 DRM driver used to do polling for completion, busy
> > waiting. It moved to be interrupt driven, which is usually better
> > for power, but it will show up as more wakeups in powertop....
>
> IOW, this is not a regression?

I don't know about this specifc case (not enough information) but for
the case I described it's not a regression. Going to interrupt driven
from busy waiting is an improvement not a regression :)

--
Arjan van de Ven Intel Open Source Technology Centre
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