busy_worker_rebind_fn() can't return until all idle workers are rebound.
This order is ensured by rebind_workers() currently.
We use synchronize_all_idles_rebound() to wait for all idle workers
to be rebound. this is an explicit way and it will ease the pain of
the rebind_workers().
The sleeping synchronize_all_idles_rebound() must be called before
the WORKER_REBIND has been cleared.
It adds a small overhead to the unlikely path.
Signed-off-by: Lai Jiangshan <la...@cn.fujitsu.com>
---
kernel/workqueue.c | 16 +++++++++++++++-
1 files changed, 15 insertions(+), 1 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index c875951..16bcd84 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1387,9 +1387,23 @@ static void busy_worker_rebind_fn(struct work_struct
*work)
{
struct worker *worker = container_of(work, struct worker, rebind_work);
struct global_cwq *gcwq = worker->pool->gcwq;
+ struct idle_rebind *idle_rebind;
+
+ if (worker_maybe_bind_and_lock(worker)) {
+ /* Is idle-rebinding still in progress? */
+ if ((idle_rebind = gcwq->idle_rebind) != NULL) {
+ /* get reference */
+ BUG_ON(idle_rebind->ref_cnt <= 0);
+ idle_rebind->ref_cnt++;
+ spin_unlock_irq(&gcwq->lock);
+
+ synchronize_all_idles_rebound(gcwq, idle_rebind);
+
+ spin_lock_irq(&gcwq->lock);
+ }
- if (worker_maybe_bind_and_lock(worker))
worker_clr_flags(worker, WORKER_REBIND);
+ }
spin_unlock_irq(&gcwq->lock);
}
--
1.7.4.4
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