Commit 2cd4d0ea authored by Ingo Molnar's avatar Ingo Molnar
Browse files

[PATCH] sched: make cpu_clock() not use the rq clock 



it is enough to disable interrupts to get the precise rq-clock
of the local CPU.

this also solves an NMI watchdog regression: the NMI watchdog
calls touch_softlockup_watchdog(), which might deadlock on
rq->lock if the NMI hits an rq-locked critical section.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 018a2212

kernel/sched.c

+3 −4
Original line number Diff line number Diff line
@@ -383,13 +383,12 @@ static inline unsigned long long rq_clock(struct rq *rq) 
 */

unsigned long long cpu_clock(int cpu)

{

	struct rq *rq = cpu_rq(cpu);

	unsigned long long now;

	unsigned long flags;



	spin_lock_irqsave(&rq->lock, flags);

	now = rq_clock(rq);

	spin_unlock_irqrestore(&rq->lock, flags);

	local_irq_save(flags);

	now = rq_clock(cpu_rq(cpu));

	local_irq_restore(flags);



	return now;

}

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