[tip:tracing/urgent] trace_stat: Don't increment @pos in seq start()

tip-bot for Li Zefan
2009-06-24T09:46:50Z

Commit-ID: 2961bf345fd1b736c3db46cad0f69855f67fbe9c
Gitweb: http://git.kernel.org/tip/2961bf345fd1b736c3db46cad0f69855f67fbe9c
Author: Li Zefan <lizf@cn.fujitsu.com>
AuthorDate: Wed, 24 Jun 2009 09:53:26 +0800
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 24 Jun 2009 11:02:51 +0200

trace_stat: Don't increment @pos in seq start()

It's wrong to increment @pos in stat_seq_start(). It causes some
stat entries lost when reading stat file, if the output of the file
is larger than PAGE_SIZE.

Reviewed-by: Liming Wang <liming.wang@windriver.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A418716.90209@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
kernel/trace/trace_stat.c | 6 +-----
1 files changed, 1 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index c006437..e66f5e4 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -199,17 +199,13 @@ static void *stat_seq_start(struct seq_file *s, loff_t *pos)
mutex_lock(&session->stat_mutex);

/* If we are in the beginning of the file, print the headers */
- if (!*pos && session->ts->stat_headers) {
- (*pos)++;
+ if (!*pos && session->ts->stat_headers)
return SEQ_START_TOKEN;
- }

node = rb_first(&session->stat_root);
for (i = 0; node && i < *pos; i++)
node = rb_next(node);

- (*pos)++;
-
return node;
}