linux-kernel - [RFC 0/3] perf tools: Show time info (v1)

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Date:	Mon,  2 Dec 2013 15:53:16 +0900
From:	Namhyung Kim <namhyung@...nel.org>
To:	Arnaldo Carvalho de Melo <acme@...stprotocols.net>
Cc:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Paul Mackerras <paulus@...ba.org>,
	Ingo Molnar <mingo@...nel.org>,
	Namhyung Kim <namhyung.kim@....com>,
	LKML <linux-kernel@...r.kernel.org>,
	Jiri Olsa <jolsa@...hat.com>, David Ahern <dsahern@...il.com>,
	Stephane Eranian <eranian@...gle.com>,
	Andi Kleen <andi@...stfloor.org>,
	Pekka Enberg <penberg@...nel.org>,
	Frederic Weisbecker <fweisbec@...il.com>
Subject: [RFC 0/3] perf tools: Show time info (v1)

Hi,

Sometimes users might want to see time information along with the
performance result but the perf cannot provide it currently.

In this patchset, I added such feature using sample->time.  When the
perf processes sample events, it calculate time info and update last
timestamp.  It keeps the last timestamp for each evsel (and for each
cpu if it's a per-cpu session).

It guesses whether a session is per-cpu if it found PERF_SAMPLE_CPU in
a evsel->attr.sample_type since I couldn't find a better way.  However
it'll have a trouble if used with tracepoint events since they require
the cpu info in the sample_type even for the per-thread sessions.

The sample time will usually be proportional to the overhead but
sometimes it show a different result especially in idle state.

With this patch, perf report can show time information in the header
(on --stdio output only for now) and a new column which can be enabled
by --show-time-info option.

  $ perf record -- perf bench sched messaging
  $ perf report --stdio --show-time-info

  # Samples: 10K of event 'cycles'
  # Event count (approx.): 5168954556
  # Total sampling time  : 0.179102 (sec)       <--- here
  #
  # Overhead        Time          Command       Shared Object                        Symbol
  # ........  ..........  ...............  ..................  ............................
  #
       6.59%    0.006093  sched-messaging  [unknown]           [.] 0x0000003153ebc7ed
       4.81%    0.005354  sched-messaging  [kernel.kallsyms]   [k] copy_user_generic_string
       3.89%    0.004098  sched-messaging  [kernel.kallsyms]   [k] avc_has_perm_flags
       3.77%    0.003630  sched-messaging  [kernel.kallsyms]   [k] unix_stream_recvmsg
       3.37%    0.003733  sched-messaging  [kernel.kallsyms]   [k] _raw_spin_lock
       2.97%    0.003489  sched-messaging  [kernel.kallsyms]   [k] _raw_spin_lock_irqsave
       2.73%    0.002615  sched-messaging  [kernel.kallsyms]   [k] __slab_free
       2.56%    0.002392  sched-messaging  [kernel.kallsyms]   [k] page_fault
       2.45%    0.002572  sched-messaging  [kernel.kallsyms]   [k] sock_alloc_send_pskb

I put the series on 'perf/time-sample-v1' branch in my tree:

  git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git

Any comments are welcome, thanks
Namhyung


Namhyung Kim (3):
  perf tools: Record total sampling time
  perf tools: Record sampling time for each entry
  perf report: Add --show-time-info option

 tools/perf/builtin-annotate.c |  2 +-
 tools/perf/builtin-diff.c     |  2 +-
 tools/perf/builtin-report.c   | 26 +++++++++++++----
 tools/perf/builtin-top.c      |  2 +-
 tools/perf/tests/hists_link.c |  4 +--
 tools/perf/ui/hist.c          | 68 ++++++++++++++++++++++++++++++++++++-------
 tools/perf/util/evsel.h       |  3 ++
 tools/perf/util/hist.c        | 15 ++++++----
 tools/perf/util/hist.h        |  4 ++-
 tools/perf/util/session.c     | 49 +++++++++++++++++++++++++++++++
 tools/perf/util/sort.h        |  1 +
 tools/perf/util/symbol.h      |  3 +-
 12 files changed, 151 insertions(+), 28 deletions(-)

-- 
1.7.11.7

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