Re: [PATCH 5/6] perf_counter: add more context information

[Peter Zijlstra]

On Mon, 2009-04-06 at 14:15 -0700, Corey Ashford wrote:
> 
> Peter Zijlstra wrote:
> > On Mon, 2009-04-06 at 13:16 -0700, Corey Ashford wrote:
> > 
> >>>> One downside of this approach is that you if you specify "no header" 
> >>>> (currently not possible, but maybe later?), you will not be able to get 
> >>>> the level bits.
> >>> Would this be desirable? 
> > 
> >> I think it would.  For one use case I'm working on right now, simple 
> >> profiling, all I need are ip's.  If I could omit the header, that would 
> >> reduce the frequency of sigio's by a factor of three, and make it faster 
> >> to read up the ip's when the SIGIO's occur.
> > 
> > Self-profiling?
> > 
> > So you're interested in getting the smallest possible record size, that
> > would still be 2 u64, right? Otherwise you don't get the IP context that
> > started this.
> > 
> > 
> 
> Self-profiling mainly, yes.  PAPI specs an ability for remote monitoring 
> of processes and threads, but I think it's only partially implemented.
> 
> So when you are talking about IP context, you mean pid/tid?

Ah, we called it level before, the hv/kernel/user thing. For remote
profiling you'd want to have the mmap thing too.



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