[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: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar 2007-07-26 13:40:43 +02:00
parent 018a221295
commit 2cd4d0ea19

View file

@ -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;
}