Re: [PATCH 8/8] Call tick_check_idle before __irq_enter

Yong Zhang
2010-10-17T09:06:13Z

On Mon, Oct 04, 2010 at 05:03:23PM -0700, Venkatesh Pallipadi wrote:
> diff --git a/kernel/softirq.c b/kernel/softirq.c
> index 267f7b7..6bb7e19 100644
> --- a/kernel/softirq.c
> +++ b/kernel/softirq.c
> @@ -296,10 +296,16 @@ void irq_enter(void)
>
> rcu_irq_enter();
> if (idle_cpu(cpu) && !in_interrupt()) {
> - __irq_enter();
> + /*
> + * Prevent raise_softirq from needlessly waking up ksoftirqd
> + * here, as softirq will be serviced on return from interrupt.
> + */
> + local_bh_disable();
> tick_check_idle(cpu);
> - } else
> - __irq_enter();
> + local_bh_enable();

_local_bh_enable()

local_bh_enable() could invoke do_softirq().

> + }
> +
> + __irq_enter();
> }
>
> #ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED
> --
> 1.7.1
>
> --
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