linux-kernel - Re: [PATCH 3/3] perf tools: Fix buildid processing

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Date:	Wed, 19 Aug 2015 18:23:51 +0300
From:	Adrian Hunter <adrian.hunter@...el.com>
To:	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Arnaldo Carvalho de Melo <arnaldo.melo@...il.com>,
	Jiri Olsa <jolsa@...hat.com>, Jiri Olsa <jolsa@...nel.org>
CC:	linux-kernel@...r.kernel.org, torvalds@...ux-foundation.org,
	mingo@...nel.org
Subject: Re: [PATCH 3/3] perf tools: Fix buildid processing

On 19/08/2015 5:29 p.m., Adrian Hunter wrote:
> After recording, 'perf record' post-processes the data to
> determine which buildids are needed. That processing must
> process the data in time order, if possible, because
> otherwise dependent events, like forks and mmaps, will
> not make sense.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
> ---
>   tools/perf/builtin-record.c | 11 +++++++++++
>   1 file changed, 11 insertions(+)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index de165a1b9240..f36b88938499 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -500,6 +500,15 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>   		return -1;
>   	}
>
> +	/*
> +	 * Normally perf_session__new would do this, but it doesn't have the
> +	 * evlist.
> +	 */
> +	if (rec->tool.ordered_events && !perf_evlist__sample_id_all(rec->evlist)) {
> +		dump_printf("WARNING: No sample_id_all support, falling back to unordered processing\n");
> +		rec->tool.ordered_events = false;
> +	}
> +

In fact this chunk is misplaced, it needs to be below the call to record__open()
after which the attributes are correctly configured.  And dump_printf() is no good
for 'perf record', pr_debug would be better. Don't have time to do that right now,
I'll do it tommorow unless Arnaldo fixes it up.

>   	fd = perf_data_file__fd(file);
>   	rec->session = session;
>
> @@ -965,9 +974,11 @@ static struct record record = {
>   	.tool = {
>   		.sample		= process_sample_event,
>   		.fork		= perf_event__process_fork,
> +		.exit		= perf_event__process_exit,
>   		.comm		= perf_event__process_comm,
>   		.mmap		= perf_event__process_mmap,
>   		.mmap2		= perf_event__process_mmap2,
> +		.ordered_events	= true,
>   	},
>   };
>
>
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