Re: [PATCH 20/41] perf tools: Let a user specify a PMU event without any config terms

From: Jiri Olsa
Date: Sat Aug 30 2014 - 04:54:27 EST

On Fri, Aug 29, 2014 at 09:48:51PM +0300, Adrian Hunter wrote:
> On 16/07/2014 9:22 p.m., Jiri Olsa wrote:
> >On Wed, Jul 16, 2014 at 06:04:44PM +0300, Adrian Hunter wrote:
> >>On 16/07/2014 5:25 p.m., Jiri Olsa wrote:
> >>>On Mon, Jul 14, 2014 at 01:02:44PM +0300, Adrian Hunter wrote:
> >>>>This enables a PMU event to be specified in the form:
> >>>>
> >>>> pmu//
> >>>>
> >>>>which is effectively the same as:
> >>>>
> >>>> pmu/config=0/
> >>>>
> >>>>This patch is a precursor to defining
> >>>>default config for a PMU.
> >>>
> >>>I understand the need for default config, but could you please elaborate
> >>>why do we want to parse 'pmu//' as an event string string?
> >>
> >>Currently the parser requires the slashes to identify a PMU event
> >>as opposed to a hardware or other kind of event.
> >
> >right, so why do we want to parse 'pmu//' as an event string? ;-)
> I am not sure what you mean. Here I am using 'pmu' as a placeholder
> for a real PMU name. So actual event strings are 'intel_bts//' or
> 'intel_pt//' or 'intel_pt/tsc=0,noretcomp=1/'

so the consequence of default arguments is that you can
specify event just by the pmu name, like:
-e intel_pt//

which means (with default attributes):
-e intel_pt/tsc=1,noretcomp=0/

I guess I wanted to hear more elaboration why is this better
than the current way we have by defining an alias, like:

krava alias: "tsc=1,noretcomp=0"

-e intel_pt/krava/

which gives the same result

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at