[PATCH 06/31] workqueue: introduce for_each_pool()

Tejun Heo
2013-03-02T03:25:00Z

With the scheduled unbound pools with custom attributes, there will be
multiple unbound pools, so it wouldn't be able to use
for_each_wq_cpu() + for_each_std_worker_pool() to iterate through all
pools.

Introduce for_each_pool() which iterates through all pools using
worker_pool_idr and use it instead of for_each_wq_cpu() +
for_each_std_worker_pool() combination in freeze_workqueues_begin().

Signed-off-by: Tejun Heo <tj@kernel.org>
---
kernel/workqueue.c | 36 +++++++++++++++++++++---------------
1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0055a31..869dbcc 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -295,6 +295,14 @@ static inline int __next_wq_cpu(int cpu, const struct cpumask *mask,
(cpu) = __next_wq_cpu((cpu), cpu_online_mask, 3))

/**
+ * for_each_pool - iterate through all worker_pools in the system
+ * @pool: iteration cursor
+ * @id: integer used for iteration
+ */
+#define for_each_pool(pool, id) \
+ idr_for_each_entry(&worker_pool_idr, pool, id)
+
+/**
* for_each_pwq - iterate through all pool_workqueues of the specified workqueue
* @pwq: iteration cursor
* @wq: the target workqueue
@@ -3589,33 +3597,31 @@ EXPORT_SYMBOL_GPL(work_on_cpu);
*/
void freeze_workqueues_begin(void)
{
- unsigned int cpu;
+ struct worker_pool *pool;
+ int id;

spin_lock_irq(&workqueue_lock);

WARN_ON_ONCE(workqueue_freezing);
workqueue_freezing = true;

- for_each_wq_cpu(cpu) {
- struct worker_pool *pool;
+ for_each_pool(pool, id) {
struct workqueue_struct *wq;

- for_each_std_worker_pool(pool, cpu) {
- spin_lock(&pool->lock);
-
- WARN_ON_ONCE(pool->flags & POOL_FREEZING);
- pool->flags |= POOL_FREEZING;
+ spin_lock(&pool->lock);

- list_for_each_entry(wq, &workqueues, list) {
- struct pool_workqueue *pwq = get_pwq(cpu, wq);
+ WARN_ON_ONCE(pool->flags & POOL_FREEZING);
+ pool->flags |= POOL_FREEZING;

- if (pwq && pwq->pool == pool &&
- (wq->flags & WQ_FREEZABLE))
- pwq->max_active = 0;
- }
+ list_for_each_entry(wq, &workqueues, list) {
+ struct pool_workqueue *pwq = get_pwq(pool->cpu, wq);

- spin_unlock(&pool->lock);
+ if (pwq && pwq->pool == pool &&
+ (wq->flags & WQ_FREEZABLE))
+ pwq->max_active = 0;
}
+
+ spin_unlock(&pool->lock);
}

spin_unlock_irq(&workqueue_lock);
--
1.8.1.2