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From: Li Zefan <lizf@cn.fujitsu.com>
To: Frederic Weisbecker <fweisbec@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 1/3] tracing/stat: change dummpy_cmp() to return -1
Date: Wed, 27 May 2009 11:04:26 +0800	[thread overview]
Message-ID: <4A1CADBA.7000707@cn.fujitsu.com> (raw)

Currently the output of trace_stat/workqueues is totally reversed:

 # cat /debug/tracing/trace_stat/workqueues
    ...
    1       17       17      210       37   `-blk_unplug_work+0x0/0x57
    1     3779     3779      181       11   |-cfq_kick_queue+0x0/0x2f
    1     3796     3796                     kblockd/1:120
    ...

The correct output should be:

    1     3796     3796                     kblockd/1:120
    1     3779     3779      181       11   |-cfq_kick_queue+0x0/0x2f
    1       17       17      210       37   `-blk_unplug_work+0x0/0x57

It's caused by "tracing/stat: replace linked list by an rbtree for sorting"
(53059c9b67a62a3dc8c80204d3da42b9267ea5a0).

dummpy_cmp() should return -1, so rb_node will always be inserted as
right-most node in the rbtree, thus we sort the output in ascending
order.

[ Impact: fix the output of trace_stat/workqueues ]

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 kernel/trace/trace_stat.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index 2e849b5..8b7420a 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -127,7 +127,7 @@ insert_stat(struct rb_root *root, struct stat_node *data, cmp_stat_t cmp)
  */
 static int dummy_cmp(void *p1, void *p2)
 {
-	return 1;
+	return -1;
 }
 
 /*
-- 
1.5.4.rc3



             reply	other threads:[~2009-05-27  3:03 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-27  3:04 Li Zefan [this message]
2009-05-27  3:04 ` [PATCH 2/3] tracing/stat: remember to free root node Li Zefan
2009-05-27  3:05 ` [PATCH 3/3] tracing/stat: do some cleanups Li Zefan
2009-05-27  3:42   ` [PATCH 3/3 -v2] " Li Zefan
  -- strict thread matches above, loose matches on Subject: below --
2009-05-28 16:42 [PATCH 0/3] tracing/stat: fixes, cleanups Frederic Weisbecker
2009-05-28 16:42 ` [PATCH 1/3] tracing/stat: change dummpy_cmp() to return -1 Frederic Weisbecker

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