Re: [PATCH 0/9] perf: Adding better precise_ip field handling

[Peter Zijlstra]

On Fri, May 10, 2013 at 11:40:53AM +0200, Jiri Olsa wrote:
> nope, but I need a automated way to find out if PEBS
> is supported in system

Create an event, see what happens ;-) But I suppose you want to know if it
should have worked vs does it actually work? Yeah, I suppose what you did
is the right thing there.

I was just completely missing the rationale earlier.

> > > having maximum precise enabled with just single 'p' seemed
> > > like good idea
> > 
> > Doesn't seem like to me; that takes away the possibility to use less.
> 
> hm, we could have another modifier to get system precise value
> 'P' maybe.. and keep the 'p' logic

That might be a possibility indeed.

> > Also, you really don't need the max_precise for that either. At worst you'll
> > have a number of unsuccessful event creations.
> 
> so you mean just detect that by opening events with increasing
> precise and see how far we could get.. could be I guess, though
> the 'precise' sysfs attribute seems more fit to me

The other way around, start at ppp end at !p, then use the one that worked.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/