linux-kernel - [tip:perf/urgent] perf tools: Put caller above callee in --children mode

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Date:   Wed, 24 May 2017 00:07:10 -0700
From:   tip-bot for Namhyung Kim <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     acme@...hat.com, hpa@...or.com, jolsa@...nel.org,
        milian.wolff@...b.com, mingo@...nel.org, peterz@...radead.org,
        yao.jin@...ux.intel.com, tglx@...utronix.de,
        torvalds@...ux-foundation.org, fweisbec@...il.com,
        namhyung@...nel.org, linux-kernel@...r.kernel.org, acme@...nel.org,
        jolsa@...hat.com
Subject: [tip:perf/urgent] perf tools: Put caller above callee in --children
 mode

Commit-ID:  7111ffff60a68f55d864200cd6c7677319e5c242
Gitweb:     http://git.kernel.org/tip/7111ffff60a68f55d864200cd6c7677319e5c242
Author:     Namhyung Kim <namhyung@...nel.org>
AuthorDate: Wed, 24 May 2017 15:21:29 +0900
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Wed, 24 May 2017 08:41:49 +0200

perf tools: Put caller above callee in --children mode

The __hpp__sort_acc() sorts entries using callchain depth in order to
put callers above in children mode.  But it assumed the callchain order
was callee-first.  Now default (for children) is caller-first so the
order of entries is reverted.

For example, consider following case:

  $ perf report --no-children
  ..l
  # Overhead  Command  Shared Object        Symbol
  # ........  .......  ...................  ..........................
  #
      99.44%  a.out    a.out                [.] main
              |
              ---main
                 __libc_start_main
                 _start

Then children mode should show 'start' above '__libc_start_main' since
it's the caller (parent) of the __libc_start_main.  But it's reversed:

  # Children      Self  Command  Shared Object    Symbol
  # ........  ........  .......  ...............  .....................
  #
      99.61%     0.00%  a.out    libc-2.25.so     [.] __libc_start_main
      99.61%     0.00%  a.out    a.out            [.] _start
      99.54%    99.44%  a.out    a.out            [.] main

This patch fixes it.

  # Children      Self  Command  Shared Object    Symbol
  # ........  ........  .......  ...............  .....................
  #
      99.61%     0.00%  a.out    a.out            [.] _start
      99.61%     0.00%  a.out    libc-2.25.so     [.] __libc_start_main
      99.54%    99.44%  a.out    a.out            [.] main

Signed-off-by: Namhyung Kim <namhyung@...nel.org>
Acked-by: Jiri Olsa <jolsa@...nel.org>
Cc: Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: Arnaldo Carvalho de Melo <acme@...hat.com>
Cc: Frederic Weisbecker <fweisbec@...il.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Milian Wolff <milian.wolff@...b.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Yao Jin <yao.jin@...ux.intel.com>
Cc: kernel-team@....com
Link: http://lkml.kernel.org/r/20170524062129.32529-8-namhyung@kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 tools/perf/ui/hist.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/ui/hist.c b/tools/perf/ui/hist.c
index 59addd5..ddb2c6f 100644
--- a/tools/perf/ui/hist.c
+++ b/tools/perf/ui/hist.c
@@ -210,6 +210,8 @@ static int __hpp__sort_acc(struct hist_entry *a, struct hist_entry *b,
 			return 0;
 
 		ret = b->callchain->max_depth - a->callchain->max_depth;
+		if (callchain_param.order == ORDER_CALLER)
+			ret = -ret;
 	}
 	return ret;
 }