From 1befcf3073fa083e7dc48c384ce06f3bd900f514 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 1 Apr 2013 11:23:35 -0700 Subject: 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: Tejun Heo Reviewed-by: Lai Jiangshan --- kernel/workqueue.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 07ec574..3825c14 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -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; -- cgit v1.1