Re: 'perf stat --repeat N' oddity/regression

From: Arnaldo Carvalho de Melo
Date: Mon Jan 25 2016 - 14:48:50 EST


Em Mon, Jan 25, 2016 at 04:43:33PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Mon, Jan 25, 2016 at 07:35:11PM +0100, Ingo Molnar escreveu:
> >
> > So it appears it broke somewhere between v4.0 and v4.1, as the v4.0 install
> > displays:
> >
> > 16,244,802,268 instructions ( +- 23.01% )
> >
> > 2.108676769 seconds time elapsed ( +- 0.86% )
> >
> >
> > [a few minutes later]
> >
> > Bisected it down to:
>
> Mel Gorman reported this and Jiri provided a patch that Mel tested and
> verified that it fixed, checking where it is sitting now...

I already sent it your way, its:

198 N C 01/21 Arnaldo Carvalh (1.4K) ââ>[PATCH 06/16] perf stat: Do not clean event's private stats

Please pull my perf-core-for-mingo tag and you should get it, its an one
liner.

- Arnaldo

> - Arnaldo
>
> > 106a94a0f8c207ef4113ce7e32f34a00b3b174e7 is the first bad commit
> > commit 106a94a0f8c207ef4113ce7e32f34a00b3b174e7
> > Author: Jiri Olsa <jolsa@xxxxxxxxxx>
> > Date: Fri Jun 26 11:29:19 2015 +0200
> >
> > perf stat: Introduce read_counters function
> >
> > So this look like to be a regression.
> >
> > Thanks,
> >
> > Ingo