Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
workqueue: Make wq_adjust_max_active() round-robin pwqs while activating
wq_adjust_max_active() needs to activate work items after max_active is
increased. Previously, it did that by visiting each pwq once activating all
that could be activated. While this makes sense with per-pwq nr_active,
nr_active will be shared across multiple pwqs for unbound wqs. Then, we'd
want to round-robin through pwqs to be fairer.
In preparation, this patch makes wq_adjust_max_active() round-robin pwqs
while activating. While the activation ordering changes, this shouldn't
cause user-noticeable behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
+19
-12
+19
-12
kernel/workqueue.c
+19
-12
kernel/workqueue.c
···
4710
4710
*/
4711
4711
static void wq_adjust_max_active(struct workqueue_struct *wq)
4712
4712
{
4713
-
struct pool_workqueue *pwq;
4713
+
bool activated;
4714
4714
4715
4715
lockdep_assert_held(&wq->mutex);
4716
4716
···
4730
4730
*/
4731
4731
WRITE_ONCE(wq->max_active, wq->saved_max_active);
4732
4732
4733
-
for_each_pwq(pwq, wq) {
4734
-
unsigned long flags;
4733
+
/*
4734
+
* Round-robin through pwq's activating the first inactive work item
4735
+
* until max_active is filled.
4736
+
*/
4737
+
do {
4738
+
struct pool_workqueue *pwq;
4735
4739
4736
-
/* this function can be called during early boot w/ irq disabled */
4737
-
raw_spin_lock_irqsave(&pwq->pool->lock, flags);
4740
+
activated = false;
4741
+
for_each_pwq(pwq, wq) {
4742
+
unsigned long flags;
4738
4743
4739
-
while (pwq_activate_first_inactive(pwq))
4740
-
;
4741
-
4742
-
kick_pool(pwq->pool);
4743
-
4744
-
raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
4745
-
}
4744
+
/* can be called during early boot w/ irq disabled */
4745
+
raw_spin_lock_irqsave(&pwq->pool->lock, flags);
4746
+
if (pwq_activate_first_inactive(pwq)) {
4747
+
activated = true;
4748
+
kick_pool(pwq->pool);
4749
+
}
4750
+
raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
4751
+
}
4752
+
} while (activated);
4746
4753
}
4747
4754
4748
4755
__printf(1, 4)