[PATCH 3.12 047/113] sched/debug: Don't dump sched debug info in SysRq-W

[Jiri Slaby]

From: Rabin Vincent <rabinv@xxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit fb90a6e93c0684ab2629a42462400603aa829b9c upstream.

sysrq_sched_debug_show() can dump a lot of information.  Don't print out
all that if we're just trying to get a list of blocked tasks (SysRq-W).
The information is still accessible with SysRq-T.

Signed-off-by: Rabin Vincent <rabinv@xxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1459777322-30902-1-git-send-email-rabin.vincent@xxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Nikolay Borisov <n.borisov.lkml@xxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 kernel/sched/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index fe080adbe5a8..426193802b1f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4233,7 +4233,8 @@ void show_state_filter(unsigned long state_filter)
 	touch_all_softlockup_watchdogs();
 
 #ifdef CONFIG_SCHED_DEBUG
-	sysrq_sched_debug_show();
+	if (!state_filter)
+		sysrq_sched_debug_show();
 #endif
 	rcu_read_unlock();
 	/*
-- 
2.12.0