powerpc: Fix races with irq_work
If we set irq_work on a processor and immediately afterward, before the irq work has a chance to be processed, we change the decrementer value, we can seriously delay the handling of that irq_work. Fix it by checking in a few places for pending irq work, first before changing the decrementer in decrementer_set_next_event() and after changing it in the same function and in timer_interrupt(). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
parent
30c826358d
commit
0215f7d8c5
|
@ -536,6 +536,9 @@ void timer_interrupt(struct pt_regs * regs)
|
|||
now = *next_tb - now;
|
||||
if (now <= DECREMENTER_MAX)
|
||||
set_dec((int)now);
|
||||
/* We may have raced with new irq work */
|
||||
if (test_irq_work_pending())
|
||||
set_dec(1);
|
||||
__get_cpu_var(irq_stat).timer_irqs_others++;
|
||||
}
|
||||
|
||||
|
@ -802,8 +805,16 @@ static void __init clocksource_init(void)
|
|||
static int decrementer_set_next_event(unsigned long evt,
|
||||
struct clock_event_device *dev)
|
||||
{
|
||||
/* Don't adjust the decrementer if some irq work is pending */
|
||||
if (test_irq_work_pending())
|
||||
return 0;
|
||||
__get_cpu_var(decrementers_next_tb) = get_tb_or_rtc() + evt;
|
||||
set_dec(evt);
|
||||
|
||||
/* We may have raced with new irq work */
|
||||
if (test_irq_work_pending())
|
||||
set_dec(1);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in a new issue