Re: [PATCH 4/6 -tip] perf_counter: Add Generalized Hardware interrupt support for AMD

[Ingo Molnar <mingo@elte.hu>]

* Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:

> On Wed, 2009-07-01 at 13:24 +0200, Ingo Molnar wrote:
> > * Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:
> > 
> > > 
> > > $ ./perf stat -e interrupts -e masked -e int-pending-mask-cycles -- ls -lR /usr/include/ > /dev/null
> > > 
> > >  Performance counter stats for 'ls -lR /usr/include/':
> > > 
> > >             377  interrupts
> > >        53429936  int-mask-cycles
> > >            1119  int-pending-mask-cycles
> > > 
> > >     0.371457539  seconds time elapsed
> > 
> > Agreed, this is another useful generalization - and the 'cycles 
> > pending' metrics are not retrievable via any software means.
> > 
> > We could and should probably add a software counter for hardirqs 
> > as wel. That would allow the vector/irqnr information to be 
> > passed in, and it would allow architectures without irq metrics 
> > in the PMU to have this counter too.
> > 
> 
> Please let me know that addition of software counter will be in 
> this patch or we can do it incrementally after this patch.

It should be in this series. That way we can cross-check whether the 
soft counts and the hard counts match up and find potential bugs 
that way, etc.

	Ingo