Re: Patch for tracing c states (power_end) on x86

[Peter Zijlstra <peterz@infradead.org>]

On Thu, 2010-03-11 at 07:36 +0100, Robert Schöne wrote:
> Did anyone look at the problem described and checked the patch?
> I still received no reply.

Ingo, how about applying it and letting people complain when they don't
agree? :-)

> Am Donnerstag, den 25.02.2010, 13:52 +0100 schrieb Peter Zijlstra:
> > On Wed, 2010-02-24 at 09:19 +0100, Robert Schöne wrote:
> > > Hello,
> > > 
> > > Since noone replied to my last mail (Febr. 15th, 11:42), describing the
> > > way to fix the missing c-state tracing, here's a patch.
> > > Maybe its easier that way.
> > > 
> > > (I used the perf-fixes-for-linus git tree to obtain a
> > > more-then-up-to-date version)
> > 
> > Arjan, any comments?, you seem skilled with this power stuff ;-)
> > 
> > > diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
> > > index 02d6780..b1cfb88 100644
> > > --- a/arch/x86/kernel/process.c
> > > +++ b/arch/x86/kernel/process.c
> > > @@ -384,6 +384,7 @@ void default_idle(void)
> > >                 else
> > >                         local_irq_enable();
> > >                 current_thread_info()->status |= TS_POLLING;
> > > +               trace_power_end(1);
> > >         } else {
> > >                 local_irq_enable();
> > >                 /* loop is done by the caller */
> > > @@ -451,6 +452,7 @@ void mwait_idle_with_hints(unsigned long ax,
> > > unsigned long cx)
> > >                 if (!need_resched())
> > >                         __mwait(ax, cx);
> > >         }
> > > +       trace_power_end((ax>>4)+1);
> > >  }
> > >  
> > >  /* Default MONITOR/MWAIT with no hints, used for default C1 state */
> > > @@ -467,6 +469,7 @@ static void mwait_idle(void)
> > >                         __sti_mwait(0, 0);
> > >                 else
> > >                         local_irq_enable();
> > > +               trace_power_end(1);
> > >         } else
> > >                 local_irq_enable();
> > >  }
> > > 
> >