Re: [PATCH v3 3/8] workqueue: Implement BH workqueues to eventually replace tasklets

[Hillf Danton <hdanton@sina.com>]

On Sun, 4 Feb 2024 11:28:06 -1000 Tejun Heo <tj@kernel.org>
> +static void bh_worker(struct worker *worker)
> +{
> +	struct worker_pool *pool = worker->pool;
> +	int nr_restarts = BH_WORKER_RESTARTS;
> +	unsigned long end = jiffies + BH_WORKER_JIFFIES;
> +
> +	raw_spin_lock_irq(&pool->lock);
> +	worker_leave_idle(worker);
> +
> +	/*
> +	 * This function follows the structure of worker_thread(). See there for
> +	 * explanations on each step.
> +	 */
> +	if (!need_more_worker(pool))
> +		goto done;
> +
> +	WARN_ON_ONCE(!list_empty(&worker->scheduled));
> +	worker_clr_flags(worker, WORKER_PREP | WORKER_REBOUND);
> +
> +	do {
> +		struct work_struct *work =
> +			list_first_entry(&pool->worklist,
> +					 struct work_struct, entry);
> +
> +		if (assign_work(work, worker, NULL))
> +			process_scheduled_works(worker);
> +	} while (keep_working(pool) &&
> +		 --nr_restarts && time_before(jiffies, end));
> +
> +	worker_set_flags(worker, WORKER_PREP);
> +done:
> +	worker_enter_idle(worker);
> +	kick_pool(pool);
> +	raw_spin_unlock_irq(&pool->lock);
> +}

I see no need to exec bh works for 2ms with irq disabled.