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Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period option showing number of samples

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On Sun, Jul 23, 2017 at 07:46:05AM +0900, Namhyung Kim wrote:
> Hi Arnaldo and Taeung,
> 
> (+ Andi)
> 
> On Fri, Jul 21, 2017 at 11:47:48AM -0300, Arnaldo Carvalho de Melo wrote:
> > Em Thu, Jul 20, 2017 at 06:36:55AM +0900, Taeung Song escreveu:
> > > +++ b/tools/perf/builtin-annotate.c
> > > @@ -177,14 +177,12 @@ static int perf_evsel__add_sample(struct perf_evsel *evsel,
> > >  	 */
> > >  	process_branch_stack(sample->branch_stack, al, sample);
> > >  
> > > -	sample->period = 1;
> > >  	sample->weight = 1;
> > > -
> > >  	he = hists__add_entry(hists, al, NULL, NULL, NULL, sample, true);
> > >  	if (he == NULL)
> > >  		return -ENOMEM;
> > 
> > I split the hunk above into a separate patch, as a fix, Namhyung, can
> > you take a look at why need to unconditionally overwrite what is in
> > sample->weight as well?
> > 
> > Looks fishy as it may come with a value from the kernel, parsed in
> > perf_evsel__parse_sample(), when PERF_SAMPLE_WEIGHT is in
> > perf_event_attr->sample_type.
> > 
> > Is it that the hists code needs a sane value when PERF_SAMPLE_WEIGHT
> > isn't requested in sample_type?
> 
> It was Andi added that code originally (05484298cbfe).  IIUC the
> weight is only meaningful for some CPUs with Intel TSX and he used a
> dummy value.

It's used for more than TSX. e.g. perf mem uses it for memory latencies.

> AFAIK the hists code doesn't care of it unless weight sort key is used
> (for report).  As it's not used by annotate code, I think it'd be
> better leaving it as is (like period).

Right, it's needed when weight is specified as a sort key. But we need
a fallback in case the user specified weight in perf report, but
didn't enable it for perf record.

-Andi

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[PATCH v3 3/9] perf annotate: Fix wrong --show-total-period option showing number of samples Taeung Song <treeze.taeung@gmail.com> - 2017-07-19 23:40 +0200
  Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Arnaldo Carvalho de Melo <acme@kernel.org> - 2017-07-20 21:20 +0200
    Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Taeung Song <treeze.taeung@gmail.com> - 2017-07-21 11:50 +0200
      Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Arnaldo Carvalho de Melo <acme@kernel.org> - 2017-07-21 13:30 +0200
        Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Taeung Song <treeze.taeung@gmail.com> - 2017-07-24 04:00 +0200
          Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Arnaldo Carvalho de Melo <acme@kernel.org> - 2017-07-24 19:40 +0200
            Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Taeung Song <treeze.taeung@gmail.com> - 2017-07-24 23:30 +0200
              Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Arnaldo Carvalho de Melo <acme@kernel.org> - 2017-07-25 16:50 +0200
                Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Taeung Song <treeze.taeung@gmail.com> - 2017-07-25 18:00 +0200
                Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Arnaldo Carvalho de Melo <acme@kernel.org> - 2017-07-25 18:20 +0200
                Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Taeung Song <treeze.taeung@gmail.com> - 2017-07-26 14:00 +0200
                Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Arnaldo Carvalho de Melo <acme@kernel.org> - 2017-07-26 22:20 +0200
                Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Taeung Song <treeze.taeung@gmail.com> - 2017-07-27 17:20 +0200
              [tip:perf/core] perf annotate stdio: Fix column header when using  --show-total-period tip-bot for Taeung Song <tipbot@zytor.com> - 2017-07-26 19:30 +0200
  Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Arnaldo Carvalho de Melo <acme@kernel.org> - 2017-07-21 17:00 +0200
    Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Namhyung Kim <namhyung@kernel.org> - 2017-07-23 00:50 +0200
      Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Andi Kleen <andi@firstfloor.org> - 2017-07-23 17:50 +0200
        Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Arnaldo Carvalho de Melo <acme@kernel.org> - 2017-07-24 19:40 +0200
          Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Andi Kleen <andi@firstfloor.org> - 2017-07-24 19:50 +0200
            Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period  option showing number of samples Arnaldo Carvalho de Melo <acme@kernel.org> - 2017-07-24 20:10 +0200
  [tip:perf/core] perf annotate: Store the sample period in each  histogram bucket tip-bot for Taeung Song <tipbot@zytor.com> - 2017-07-26 19:30 +0200
  [tip:perf/core] perf annotate: Do not overwrite sample->period tip-bot for Taeung Song <tipbot@zytor.com> - 2017-07-26 19:30 +0200
  [tip:perf/core] perf hists: Pass perf_sample to  __symbol__inc_addr_samples() tip-bot for Taeung Song <tipbot@zytor.com> - 2017-07-26 19:30 +0200

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