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

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Date:   Mon, 18 Dec 2017 08:23:46 -0700
From:   Mathieu Poirier <mathieu.poirier@...aro.org>
To:     Adrian Hunter <adrian.hunter@...el.com>
Cc:     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>,
        Arnaldo Carvalho de Melo <acme@...hat.com>,
        Andi Kleen <ak@...ux.intel.com>
Subject: Re: perf record: regression with latest PT fix

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?

>
>
>>
>>> 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?
>>
>