Re: [PATCH] perf, tools: Disable branch flags/cycles for --callgraph lbr

From: Arnaldo Carvalho de Melo
Date: Mon Dec 14 2015 - 10:12:59 EST


Em Mon, Dec 14, 2015 at 10:55:38AM +0100, Jiri Olsa escreveu:
> On Fri, Dec 11, 2015 at 04:12:24PM -0800, Andi Kleen wrote:
> > From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> >
> > [The kernel patch needed for this is in tip now
> > (b16a5b52eb9 perf/x86: Add option to disable ...)
> > So this user tools patch to make use of it should be merged now]
> >
> > Automatically disable collecting branch flags and cycles with
> > --call-graph lbr. This allows avoiding a bunch of extra MSR
> > reads in the PMI on Skylake.
> >
> > When the kernel doesn't support the new flags they are automatically
> > cleared in the fallback code.
> >
> > v2: Switch to use branch_sample_type instead of sample_type.
> > Adjust description.
> > Fix the fallback logic.
> > Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
>
> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

Thanks, applied to perf/core.

- Arnaldo
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