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

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Date:   Fri, 21 Jul 2017 11:47:48 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Namhyung Kim <namhyung@...nel.org>,
        Taeung Song <treeze.taeung@...il.com>
Cc:     linux-kernel@...r.kernel.org, Milian Wolff <milian.wolff@...b.com>,
        Jiri Olsa <jolsa@...hat.com>
Subject: Re: [PATCH v3 3/9] perf annotate: Fix wrong --show-total-period
 option showing number of samples

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?

The resulting cset is below.

- Arnaldo

commit a935e8cd8d5d4b7936c4b4cf27c2d0e87d1a6a66
Author: Taeung Song <treeze.taeung@...il.com>
Date:   Fri Jul 21 11:38:48 2017 -0300

    perf annotate: Do not overwrite sample->period
    
    In fixing the --show-total-period option it was noticed that the value
    of sample->period was being overwritten, fix it.
    
    Cc: Jiri Olsa <jolsa@...hat.com>
    Cc: Milian Wolff <milian.wolff@...b.com>
    Cc: Namhyung Kim <namhyung@...nel.org>
    Fixes: fd36f3dd7933 ("perf hist: Pass struct sample to __hists__add_entry()")
    [ split from a larger patch, added the Fixes tag ]
    Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>

diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 96fe1a88c1e5..7e33278eff67 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -177,7 +177,6 @@ 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);