linux-kernel - Re: perf record: regression with latest PT fix

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Message-ID: <20171218164431.GE2777@redhat.com>
Date:   Mon, 18 Dec 2017 14:44:31 -0200
From:   Arnaldo Carvalho de Melo <acme@...hat.com>
To:     Mathieu Poirier <mathieu.poirier@...aro.org>
Cc:     Adrian Hunter <adrian.hunter@...el.com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Stephane Eranian <eranian@...gle.com>,
        Jiri Olsa <jolsa@...hat.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Andi Kleen <ak@...ux.intel.com>, acme@...nel.org
Subject: Re: perf record: regression with latest PT fix

Em Mon, Dec 18, 2017 at 08:23:46AM -0700, Mathieu Poirier escreveu:
> On 18 December 2017 at 07:25, Adrian Hunter <adrian.hunter@...el.com> wrote:
> > On 18/12/17 15:28, Alexander Shishkin wrote:
> >> On Mon, Dec 18, 2017 at 05:03:53AM -0800, Stephane Eranian wrote:
> >>> Hi,
> >>>
> >>>
> >>> The following patch:
> >>>
> >>> f785657b0fbe perf report: Fix regression when decoding Intel-PT traces
> >>
> >> Cc'ing Adrian in case he missed the patch.
> >
> > Doesn't seem to have much to do with Intel PT, but the patch logic looks wrong:
> >
> >                 ret = perf_evlist__parse_sample_timestamp(evlist, event, &timestamp);
> > -               if (ret)
> > +               if (ret != -1)
> >                         return ret;
> >
> > Shouldn't that be:
> >
> >                 ret = perf_evlist__parse_sample_timestamp(evlist, event, &timestamp);
> > -               if (ret)
> > +               if (ret && ret != -1)
> >                         return ret;
> 
> Of course!
> 
> Ingo, how do you want to proceed?  Should I send a V3?

Probably, I've run into this as well, as has Ingo, after I reverted it,
things got back working.

Back to vacations... :-)

- Arnaldo
 
> >>> is breaking perf report for me. I get no samples reported from perf report
> >>> when running simple perf record commands:
> >>>
> >>> $ perf record -e cycles noploop
> >>>
> >>> Reverting the patch fixes the problem.
> >>>
> >>> Are you seeing this as well?
> >>
> >