Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1befcf30 authored by Tejun Heo's avatar Tejun Heo
Browse files

workqueue: introduce numa_pwq_tbl_install() 



Factor out pool_workqueue linking and installation into numa_pwq_tbl[]
from apply_workqueue_attrs() into numa_pwq_tbl_install().  link_pwq()
is made safe to call multiple times.  numa_pwq_tbl_install() links the
pwq, installs it into numa_pwq_tbl[] at the specified node and returns
the old entry.

@last_pwq is removed from link_pwq() as the return value of the new
function can be used instead.

This is to prepare for NUMA affinity support for unbound workqueues.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
parent e50aba9a

kernel/workqueue.c

+26 −9
Original line number Diff line number Diff line
@@ -3639,24 +3639,26 @@ static void init_pwq(struct pool_workqueue *pwq, struct workqueue_struct *wq, 
	pwq->flush_color = -1;

	pwq->refcnt = 1;

	INIT_LIST_HEAD(&pwq->delayed_works);

	INIT_LIST_HEAD(&pwq->pwqs_node);

	INIT_LIST_HEAD(&pwq->mayday_node);

	INIT_WORK(&pwq->unbound_release_work, pwq_unbound_release_workfn);

}



/* sync @pwq with the current state of its associated wq and link it */

static void link_pwq(struct pool_workqueue *pwq,

		     struct pool_workqueue **p_last_pwq)

static void link_pwq(struct pool_workqueue *pwq)

{

	struct workqueue_struct *wq = pwq->wq;



	lockdep_assert_held(&wq->mutex);



	/* may be called multiple times, ignore if already linked */

	if (!list_empty(&pwq->pwqs_node))

		return;



	/*

	 * Set the matching work_color.  This is synchronized with

	 * wq->mutex to avoid confusing flush_workqueue().

	 */

	if (p_last_pwq)

		*p_last_pwq = first_pwq(wq);

	pwq->work_color = wq->work_color;



	/* sync max_active to the current setting */
@@ -3689,6 +3691,23 @@ static struct pool_workqueue *alloc_unbound_pwq(struct workqueue_struct *wq, 
	return pwq;

}



/* install @pwq into @wq's numa_pwq_tbl[] for @node and return the old pwq */

static struct pool_workqueue *numa_pwq_tbl_install(struct workqueue_struct *wq,

						   int node,

						   struct pool_workqueue *pwq)

{

	struct pool_workqueue *old_pwq;



	lockdep_assert_held(&wq->mutex);



	/* link_pwq() can handle duplicate calls */

	link_pwq(pwq);



	old_pwq = rcu_access_pointer(wq->numa_pwq_tbl[node]);

	rcu_assign_pointer(wq->numa_pwq_tbl[node], pwq);

	return old_pwq;

}



/**

 * apply_workqueue_attrs - apply new workqueue_attrs to an unbound workqueue

 * @wq: the target workqueue
@@ -3707,7 +3726,7 @@ int apply_workqueue_attrs(struct workqueue_struct *wq, 
			  const struct workqueue_attrs *attrs)

{

	struct workqueue_attrs *new_attrs;

	struct pool_workqueue *pwq, *last_pwq;

	struct pool_workqueue *pwq, *last_pwq = NULL;

	int node, ret;



	/* only unbound workqueues can change attributes */
@@ -3734,11 +3753,9 @@ int apply_workqueue_attrs(struct workqueue_struct *wq, 


	mutex_lock(&wq->mutex);



	link_pwq(pwq, &last_pwq);



	copy_workqueue_attrs(wq->unbound_attrs, new_attrs);

	for_each_node(node)

		rcu_assign_pointer(wq->numa_pwq_tbl[node], pwq);

		last_pwq = numa_pwq_tbl_install(wq, node, pwq);



	mutex_unlock(&wq->mutex);
@@ -3778,7 +3795,7 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq) 
			init_pwq(pwq, wq, &cpu_pools[highpri]);



			mutex_lock(&wq->mutex);

			link_pwq(pwq, NULL);

			link_pwq(pwq);

			mutex_unlock(&wq->mutex);

		}

		return 0;