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
--
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/