Re: [PATCH 5/7] perf session: don't rely on evlist in pipe mode

Arnaldo Carvalho de Melo
2017-04-11T18:40:24Z

Em Mon, Apr 10, 2017 at 01:14:30PM -0700, David Carrillo-Cisneros escreveu:
> Session sets a number parameters that rely on evlist. These parameters
> are not used in pipe-mode and should not be set, since evlist is
> unavailable. Fix that.

Ditching this one as well, until further investigation, well, file must
be null in this case...

[acme@jouet linux]$ git bisect bad
5d71c27204d51492abe9fc69064fd36a0bda410b is the first bad commit
commit 5d71c27204d51492abe9fc69064fd36a0bda410b
Author: David Carrillo-Cisneros <davidcc@google.com>
Date: Mon Apr 10 13:14:30 2017 -0700

perf session: Don't rely on evlist in pipe mode

Session sets a number parameters that rely on evlist. These parameters
are not used in pipe-mode and should not be set, since evlist is
unavailable. Fix that.

Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170410201432.24807-6-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

:040000 040000 7df28fe9d7c9d962b78c0532f4961caea2737b59 34e4fed0042b1401c1a1a247d8ae40df17f9d272 M tools
[acme@jouet linux]$

> Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
> ---
> tools/perf/util/session.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> index a25302bc55a8..db554b7461b8 100644
> --- a/tools/perf/util/session.c
> +++ b/tools/perf/util/session.c
> @@ -140,8 +140,14 @@ struct perf_session *perf_session__new(struct perf_data_file *file,
> if (perf_session__open(session) < 0)
> goto out_close;
>
> - perf_session__set_id_hdr_size(session);
> - perf_session__set_comm_exec(session);
> + /*
> + * set session attributes that are present in perf.data
> + * but not in pipe-mode.
> + */
> + if (!file->is_pipe) {
> + perf_session__set_id_hdr_size(session);
> + perf_session__set_comm_exec(session);
> + }
> }
> } else {
> session->machines.host.env = &perf_env;
> @@ -156,7 +162,11 @@ struct perf_session *perf_session__new(struct perf_data_file *file,
> pr_warning("Cannot read kernel map\n");
> }
>
> - if (tool && tool->ordering_requires_timestamps &&
> + /*
> + * In pipe-mode, evlist is empty until PERF_RECORD_HEADER_ATTR is
> + * processed, so perf_evlist__sample_id_all is not meaningful here.
> + */
> + if (!file->is_pipe && tool && tool->ordering_requires_timestamps &&
> tool->ordered_events && !perf_evlist__sample_id_all(session->evlist)) {
> dump_printf("WARNING: No sample_id_all support, falling back to unordered processing\n");
> tool->ordered_events = false;
> --
> 2.12.2.715.g7642488e1d-goog