Re: [PATCH/RFC] workqueue: allow rescuer thread to do more work.

[Tejun Heo <tj@kernel.org>]

Hello,

On Tue, Nov 11, 2014 at 09:04:02AM +1100, NeilBrown wrote:
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 09b685daee3d..f2db6073c498 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -2235,11 +2235,6 @@ repeat:
>  		struct work_struct *work, *n;
>  
>  		__set_current_state(TASK_RUNNING);
> -		list_del_init(&pwq->mayday_node);
> -
> -		spin_unlock_irq(&wq_mayday_lock);
> -
> -		worker_attach_to_pool(rescuer, pool);
>  
>  		spin_lock_irq(&pool->lock);
>  		rescuer->pool = pool;
> @@ -2253,8 +2248,16 @@ repeat:
>  			if (get_work_pwq(work) == pwq)
>  				move_linked_works(work, scheduled, &n);
>  
> -		process_scheduled_works(rescuer);
> +		if (list_empty(scheduled) || !need_to_create_worker(pool))
> +			/* We can let go of this one  now */
> +			list_del_init(&pwq->mayday_node);

We prolly want to rotate the processed one to the back of the list too
so that the rescuer round robins across multiple mayday requests?

Thanks.

-- 
tejun