linux-kernel - Re: [PATCH v5] perf annotate: Fix sample events lost in stdio mode

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Date:   Tue, 16 Mar 2021 10:07:36 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Yang Jihong <yangjihong1@...wei.com>
Cc:     peterz@...radead.org, mingo@...hat.com, mark.rutland@....com,
        alexander.shishkin@...ux.intel.com, jolsa@...hat.com,
        namhyung@...nel.org, yao.jin@...ux.intel.com,
        gustavoars@...nel.org, mliska@...e.cz,
        linux-kernel@...r.kernel.org, zhangjinhao2@...wei.com
Subject: Re: [PATCH v5] perf annotate: Fix sample events lost in stdio mode

Em Tue, Mar 16, 2021 at 10:17:59AM +0800, Yang Jihong escreveu:
> In hist__find_annotations function, since different hist_entry may point to same
> symbol, we free notes->src to signal already processed this symbol in stdio mode;
> when annotate, entry will skipped if notes->src is NULL to avoid repeated output.
> 
> However, there is a problem, for example, run the following command:
> 
>  # perf record -e branch-misses -e branch-instructions -a sleep 1
> 
> perf.data file contains different types of sample event.
> 
> If the same IP sample event exists in branch-misses and branch-instructions,
> this event uses the same symbol. When annotate branch-misses events, notes->src
> corresponding to this event is set to null, as a result, when annotate
> branch-instructions events, this event is skipped and no annotate is output.
> 
> Solution of this patch is to remove zfree in hists__find_annotations and
> change sort order to "dso,symbol" to avoid duplicate output when different
> processes correspond to the same symbol.

You forgot to add your Signed-off-by tag, i.e.:

Signed-off-by: Yang Jihong <yangjihong1@...wei.com>

Please take a look at Documentation/process/submitting-patches.rst.

Regards,

- Arnaldo

> ---
>  tools/perf/builtin-annotate.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
> index a23ba6bb99b6..92c55f292c11 100644
> --- a/tools/perf/builtin-annotate.c
> +++ b/tools/perf/builtin-annotate.c
> @@ -374,13 +374,6 @@ static void hists__find_annotations(struct hists *hists,
>  		} else {
>  			hist_entry__tty_annotate(he, evsel, ann);
>  			nd = rb_next(nd);
> -			/*
> -			 * Since we have a hist_entry per IP for the same
> -			 * symbol, free he->ms.sym->src to signal we already
> -			 * processed this symbol.
> -			 */
> -			zfree(&notes->src->cycles_hist);
> -			zfree(&notes->src);
>  		}
>  	}
>  }
> @@ -619,6 +612,12 @@ int cmd_annotate(int argc, const char **argv)
>  
>  	setup_browser(true);
>  
> +	/*
> +	 * Events of different processes may correspond to the same
> +	 * symbol, we do not care about the processes in annotate,
> +	 * set sort order to avoid repeated output.
> +	 */
> +	sort_order = "dso,symbol";
>  	if ((use_browser == 1 || annotate.use_stdio2) && annotate.has_br_stack) {
>  		sort__mode = SORT_MODE__BRANCH;
>  		if (setup_sorting(annotate.session->evlist) < 0)
> -- 
> 2.30.GIT
> 

-- 

- Arnaldo