Re: [patch V2 4/9] softirq: Make softirq control and processing RT aware

From: Frederic Weisbecker
Date: Mon Dec 07 2020 - 19:09:54 EST


On Fri, Dec 04, 2020 at 06:01:55PM +0100, Thomas Gleixner wrote:
> +static void __local_bh_enable(unsigned int cnt, bool unlock)
> +{
> + unsigned long flags;
> + int newcnt;
> +
> + DEBUG_LOCKS_WARN_ON(current->softirq_disable_cnt !=
> + this_cpu_read(softirq_ctrl.cnt));

Less important since it's debug code, but still can be __this_cpu_read().

> +
> + if (IS_ENABLED(CONFIG_TRACE_IRQFLAGS) && softirq_count() == cnt) {
> + raw_local_irq_save(flags);
> + lockdep_softirqs_on(_RET_IP_);
> + raw_local_irq_restore(flags);
> + }
> +
> + newcnt = __this_cpu_sub_return(softirq_ctrl.cnt, cnt);
> + current->softirq_disable_cnt = newcnt;
> +
> + if (!newcnt && unlock) {
> + rcu_read_unlock();
> + local_unlock(&softirq_ctrl.lock);
> + }
> +}
> +
> +static inline bool should_wake_ksoftirqd(void)
> +{
> + return !this_cpu_read(softirq_ctrl.cnt);

And that too.

Other than these boring details:

Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>

Thanks.