From: Steven Rostedt Revert commit Author: Peter Zijlstra Date: Mon Oct 3 12:43:25 2011 +0200 workqueue: Fix PF_THREAD_BOUND abuse As TREAD_BOUND no longer affects cpu down, and this code introduced a lot of races with taking down a CPU. Signed-off-by: Steven Rostedt Signed-off-by: Thomas Gleixner --- kernel/workqueue.c | 29 +++++++++-------------------- 1 file changed, 9 insertions(+), 20 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index a08a963..53268e3 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1287,14 +1287,8 @@ __acquires(&gcwq->lock) return false; if (task_cpu(task) == gcwq->cpu && cpumask_equal(¤t->cpus_allowed, - get_cpu_mask(gcwq->cpu))) { - /* - * Since we're binding to a particular cpu and need to - * stay there for correctness, mark us PF_THREAD_BOUND. - */ - task->flags |= PF_THREAD_BOUND; + get_cpu_mask(gcwq->cpu))) return true; - } spin_unlock_irq(&gcwq->lock); /* @@ -1308,18 +1302,6 @@ __acquires(&gcwq->lock) } } -static void worker_unbind_and_unlock(struct worker *worker) -{ - struct global_cwq *gcwq = worker->gcwq; - struct task_struct *task = worker->task; - - /* - * Its no longer required we're PF_THREAD_BOUND, the work is done. - */ - task->flags &= ~PF_THREAD_BOUND; - spin_unlock_irq(&gcwq->lock); -} - static struct worker *alloc_worker(void) { struct worker *worker; @@ -1382,9 +1364,15 @@ static struct worker *create_worker(struct global_cwq *gcwq, bool bind) if (IS_ERR(worker->task)) goto fail; + /* + * A rogue worker will become a regular one if CPU comes + * online later on. Make sure every worker has + * PF_THREAD_BOUND set. + */ if (bind && !on_unbound_cpu) kthread_bind(worker->task, gcwq->cpu); else { + worker->task->flags |= PF_THREAD_BOUND; if (on_unbound_cpu) worker->flags |= WORKER_UNBOUND; } @@ -2061,7 +2049,7 @@ repeat: if (keep_working(gcwq)) wake_up_worker(gcwq); - worker_unbind_and_unlock(rescuer); + spin_unlock_irq(&gcwq->lock); } schedule(); @@ -2957,6 +2945,7 @@ struct workqueue_struct *__alloc_workqueue_key(const char *name, if (IS_ERR(rescuer->task)) goto err; + rescuer->task->flags |= PF_THREAD_BOUND; wake_up_process(rescuer->task); } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/