[PATCH v4 05/19] workqueue: Manually break affinity on hotplug

[Peter Zijlstra]

Don't rely on the scheduler to force break affinity for us -- it will
stop doing that for per-cpu-kthreads.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
---
 kernel/workqueue.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4905,6 +4905,10 @@ static void unbind_workers(int cpu)
 		pool->flags |= POOL_DISASSOCIATED;
 
 		raw_spin_unlock_irq(&pool->lock);
+
+		for_each_pool_worker(worker, pool)
+			WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, cpu_active_mask) < 0);
+
 		mutex_unlock(&wq_pool_attach_mutex);
 
 		/*