freezing is nothing related to pools, but POOL_FREEZING adds a connection,
and causes freeze_workqueues_begin() and thaw_workqueues() complicated.
Since freezing is workqueue instance attribute, so we introduce wq->freezing
instead and remove POOL_FREEZING.
Signed-off-by: Lai Jiangshan <la...@cn.fujitsu.com>
---
kernel/workqueue.c | 33 +++++++--------------------------
1 files changed, 7 insertions(+), 26 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 04a8b98..6b7e5a4 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -66,7 +66,6 @@ enum {
*/
POOL_MANAGE_WORKERS = 1 << 0, /* need to manage workers */
POOL_DISASSOCIATED = 1 << 2, /* cpu can't serve workers */
- POOL_FREEZING = 1 << 3, /* freeze in progress */
/* worker flags */
WORKER_STARTED = 1 << 0, /* started */
@@ -241,6 +240,7 @@ struct workqueue_struct {
int nr_drainers; /* WQ: drain in progress */
int saved_max_active; /* WQ: saved pwq max_active */
+ bool freezing; /* WQ: the wq is freezing */
#ifdef CONFIG_SYSFS
struct wq_device *wq_dev; /* I: for sysfs interface */
@@ -3493,9 +3493,6 @@ static struct worker_pool *get_unbound_pool(const struct
workqueue_attrs *attrs)
if (!pool || init_worker_pool(pool) < 0)
goto fail;
- if (workqueue_freezing)
- pool->flags |= POOL_FREEZING;
-
lockdep_set_subclass(&pool->lock, 1); /* see put_pwq() */
copy_workqueue_attrs(pool->attrs, attrs);
@@ -3571,7 +3568,7 @@ static void pwq_adjust_max_active(struct pool_workqueue
*pwq)
struct workqueue_struct *wq = pwq->wq;
bool freezable = wq->flags & WQ_FREEZABLE;
- /* for @wq->saved_max_active */
+ /* for @wq->saved_max_active and @wq->freezing */
lockdep_assert_held(&wq->mutex);
/* fast exit for non-freezable wqs */
@@ -3580,7 +3577,7 @@ static void pwq_adjust_max_active(struct pool_workqueue
*pwq)
spin_lock_irq(&pwq->pool->lock);
- if (!freezable || !(pwq->pool->flags & POOL_FREEZING)) {
+ if (!freezable || !wq->freezing) {
pwq->max_active = wq->saved_max_active;
while (!list_empty(&pwq->delayed_works) &&
@@ -3795,6 +3792,7 @@ struct workqueue_struct *__alloc_workqueue_key(const char
*fmt,
mutex_lock(&wq_pool_mutex);
mutex_lock(&wq->mutex);
+ wq->freezing = workqueue_freezing;
for_each_pwq(pwq, wq)
pwq_adjust_max_active(pwq);
mutex_unlock(&wq->mutex);
@@ -4282,26 +4280,18 @@ EXPORT_SYMBOL_GPL(work_on_cpu);
*/
void freeze_workqueues_begin(void)
{
- struct worker_pool *pool;
struct workqueue_struct *wq;
struct pool_workqueue *pwq;
- int pi;
mutex_lock(&wq_pool_mutex);
WARN_ON_ONCE(workqueue_freezing);
workqueue_freezing = true;
- /* set FREEZING */
- for_each_pool(pool, pi) {
- spin_lock_irq(&pool->lock);
- WARN_ON_ONCE(pool->flags & POOL_FREEZING);
- pool->flags |= POOL_FREEZING;
- spin_unlock_irq(&pool->lock);
- }
-
list_for_each_entry(wq, &workqueues, list) {
mutex_lock(&wq->mutex);
+ WARN_ON_ONCE(wq->freezing);
+ wq->freezing = true;
for_each_pwq(pwq, wq)
pwq_adjust_max_active(pwq);
mutex_unlock(&wq->mutex);
@@ -4369,25 +4359,16 @@ void thaw_workqueues(void)
{
struct workqueue_struct *wq;
struct pool_workqueue *pwq;
- struct worker_pool *pool;
- int pi;
mutex_lock(&wq_pool_mutex);
if (!workqueue_freezing)
goto out_unlock;
- /* clear FREEZING */
- for_each_pool(pool, pi) {
- spin_lock_irq(&pool->lock);
- WARN_ON_ONCE(!(pool->flags & POOL_FREEZING));
- pool->flags &= ~POOL_FREEZING;
- spin_unlock_irq(&pool->lock);
- }
-
/* restore max_active and repopulate worklist */
list_for_each_entry(wq, &workqueues, list) {
mutex_lock(&wq->mutex);
+ wq->freezing = false;
for_each_pwq(pwq, wq)
pwq_adjust_max_active(pwq);
mutex_unlock(&wq->mutex);
--
1.7.7.6
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