Caculate the value(max_active) for pwq->max_active earlier.
Fast exit for max_active is not changed.
"if (!freezable && pwq->max_active == wq->saved_max_active)" is hardly
hit after __WQ_FREEZING was introduced. So we change the exit-condition
to a more possible condition.
Reduce wake_up_worker() rate.
Signed-off-by: Lai Jiangshan <la...@cn.fujitsu.com>
---
kernel/workqueue.c | 21 +++++++++++----------
1 files changed, 11 insertions(+), 10 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index beca98b..59bad6e 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -198,7 +198,7 @@ struct pool_workqueue {
int nr_in_flight[WORK_NR_COLORS];
/* L: nr of in_flight works */
int nr_active; /* L: nr of active works */
- int max_active; /* L: max active works */
+ int max_active; /* L&WQ: max active works */
struct list_head delayed_works; /* L: delayed works */
struct list_head pwqs_node; /* WR: node on wq->pwqs */
struct list_head mayday_node; /* MD: node on wq->maydays */
@@ -3756,20 +3756,23 @@ static void pwq_unbound_release_workfn(struct
work_struct *work)
static void pwq_adjust_max_active(struct pool_workqueue *pwq)
{
struct workqueue_struct *wq = pwq->wq;
- bool freezable = wq->flags & WQ_FREEZABLE;
+ int max_active = wq->saved_max_active;
/* for @wq->saved_max_active and @wq->flags */
lockdep_assert_held(&wq->mutex);
- /* fast exit for non-freezable wqs */
- if (!freezable && pwq->max_active == wq->saved_max_active)
+ if (wq->flags & __WQ_FREEZING) {
+ if (!WARN_ON_ONCE(!(wq->flags & WQ_FREEZABLE)))
+ max_active = 0;
+ }
+
+ /* fast exit for max_active is not changed */
+ if (pwq->max_active == max_active)
return;
spin_lock_irq(&pwq->pool->lock);
-
- if (!freezable || !(wq->flags & __WQ_FREEZING)) {
- pwq->max_active = wq->saved_max_active;
-
+ pwq->max_active = max_active;
+ if (pwq->nr_active < pwq->max_active) {
while (!list_empty(&pwq->delayed_works) &&
pwq->nr_active < pwq->max_active)
pwq_activate_first_delayed(pwq);
@@ -3779,8 +3782,6 @@ static void pwq_adjust_max_active(struct pool_workqueue
*pwq)
* max_active is bumped. It's a slow path. Do it always.
*/
wake_up_worker(pwq->pool);
- } else {
- pwq->max_active = 0;
}
spin_unlock_irq(&pwq->pool->lock);
--
1.7.4.4
--
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