trace_stat: Fix missing entry in stat file
One entry is missing in the output of a stat file.
The cause is, when stat_seq_start() is called the 2nd time, we
should start from the (pos-1)th elem in the rbtree but not pos,
because pos == 0 is the header.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A891A65.70009@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index 07c60b0..a4bb239 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -203,17 +203,21 @@
{
struct stat_session *session = s->private;
struct rb_node *node;
+ int n = *pos;
int i;
/* Prevent from tracer switch or rbtree modification */
mutex_lock(&session->stat_mutex);
/* If we are in the beginning of the file, print the headers */
- if (!*pos && session->ts->stat_headers)
- return SEQ_START_TOKEN;
+ if (session->ts->stat_headers) {
+ if (n == 0)
+ return SEQ_START_TOKEN;
+ n--;
+ }
node = rb_first(&session->stat_root);
- for (i = 0; node && i < *pos; i++)
+ for (i = 0; node && i < n; i++)
node = rb_next(node);
return node;