[tip:timers/urgent] nohz: Print more debug info in tick_nohz_stop_sched_tick()

From: tip-bot for Frederic Weisbecker
Date: Mon Apr 24 2017 - 13:06:59 EST


Commit-ID: 098991fccfc7c0dd5fdfc6ed2ed965ad80f14be5
Gitweb: http://git.kernel.org/tip/098991fccfc7c0dd5fdfc6ed2ed965ad80f14be5
Author: Frederic Weisbecker <fweisbec@xxxxxxxxx>
AuthorDate: Mon, 24 Apr 2017 16:04:37 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 24 Apr 2017 16:27:09 +0200

nohz: Print more debug info in tick_nohz_stop_sched_tick()

Print more debug info when triggering this warning:

> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 0 at kernel/time/tick-sched.c:874 __tick_nohz_idle_enter+0x461/0x490

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: James Hartsock <hartsjc@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tim Wright <tim@xxxxxxxxxxxxx>
Link: 20170424140436.GD21353@lerouge">http://lkml.kernel.org/r/20170424140436.GD21353@lerouge
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/time/tick-sched.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index be7ca4d..b2df684 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -789,6 +789,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
goto out;

WARN_ON_ONCE(1);
+ printk_once("basemono: %llu ts->next_tick: %llu dev->next_event: %llu\n", basemono, ts->next_tick, dev->next_event);
}

/*