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* [PATCH] nohz: Fix local_timer_softirq_pending()
@ 2018-07-31 16:13 Anna-Maria Gleixner
  2018-07-31 16:50 ` Paul E. McKenney
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Anna-Maria Gleixner @ 2018-07-31 16:13 UTC (permalink / raw)
  To: linux-kernel
  Cc: bigeasy, tglx, frederic, bristot, paulmck, peterz, Anna-Maria Gleixner

local_timer_softirq_pending() checks whether the timer softirq is
pending with: local_softirq_pending() & TIMER_SOFTIRQ.

This is wrong because TIMER_SOFTIRQ is the softirq number and not a
bitmask. So the test checks for the wrong bit.

Use BIT(TIMER_SOFTIRQ) instead.

Fixes: 5d62c183f9e9 ("nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()")
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
---
 kernel/time/tick-sched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index da9455a6b42b..5b33e2f5c0ed 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -642,7 +642,7 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
 
 static inline bool local_timer_softirq_pending(void)
 {
-	return local_softirq_pending() & TIMER_SOFTIRQ;
+	return local_softirq_pending() & BIT(TIMER_SOFTIRQ);
 }
 
 static ktime_t tick_nohz_next_event(struct tick_sched *ts, int cpu)
-- 
2.18.0


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2018-07-31 16:13 [PATCH] nohz: Fix local_timer_softirq_pending() Anna-Maria Gleixner
2018-07-31 16:50 ` Paul E. McKenney
2018-07-31 17:07 ` Daniel Bristot de Oliveira
2018-07-31 17:14 ` Frederic Weisbecker
2018-07-31 20:13 ` [tip:timers/urgent] " tip-bot for Anna-Maria Gleixner

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