Re: [PATCH 5/7] sched: Pull preemption disablement duty up to __schedule() callers

From: Peter Zijlstra
Date: Mon May 11 2015 - 11:52:32 EST


On Mon, May 11, 2015 at 05:08:22PM +0200, Frederic Weisbecker wrote:
> +++ b/kernel/sched/core.c
> @@ -2723,9 +2723,7 @@ again:
> * - return from syscall or exception to user-space
> * - return from interrupt-handler to user-space
> *
> - * WARNING: all callers must re-check need_resched() afterward and reschedule
> - * accordingly in case an event triggered the need for rescheduling (such as
> - * an interrupt waking up a task) while preemption was disabled in __schedule().
> + * WARNING: must be called with preemption disabled!
> */
> static void __sched __schedule(void)
> {
> @@ -2734,7 +2732,6 @@ static void __sched __schedule(void)
> struct rq *rq;
> int cpu;
>
> - preempt_disable();
> cpu = smp_processor_id();
> rq = cpu_rq(cpu);
> rcu_note_context_switch();
> @@ -2798,8 +2795,6 @@ static void __sched __schedule(void)
> raw_spin_unlock_irq(&rq->lock);
>
> post_schedule(rq);
> -
> - sched_preempt_enable_no_resched();
> }

Ah, see, you need to fold this patch into the previous one.
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