[tip:tracing/urgent] ftrace: Add check of sched_stopped for probe_sched_wakeup

[Zhaolei <zhaolei@cn.fujitsu.com>]

Commit-ID:  8bcae09b93e7f96f700b6bb372c2b3f2b36636dc
Gitweb:     http://git.kernel.org/tip/8bcae09b93e7f96f700b6bb372c2b3f2b36636dc
Author:     Zhaolei <zhaolei@cn.fujitsu.com>
AuthorDate: Tue, 31 Mar 2009 15:24:51 +0800
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 7 Apr 2009 14:01:11 +0200

ftrace: Add check of sched_stopped for probe_sched_wakeup

The wakeup tracing in sched_switch does not stop when a user
disables tracing. This is because the probe_sched_wakeup() is missing
the check to prevent the wakeup from being traced.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
LKML-Reference: <49D1C543.3010307@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 kernel/trace/trace_sched_switch.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index de35f20..9117cea 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -62,6 +62,9 @@ probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee, int success)
 	pc = preempt_count();
 	tracing_record_cmdline(current);
 
+	if (sched_stopped)
+		return;
+
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
 	data = ctx_trace->data[cpu];