From 06ba38a9a0f6ceffe70343f684c5a690e3710ef4 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 9 May 2007 02:34:15 -0700 Subject: [PATCH] workqueues: shift kthread_bind() from CPU_UP_PREPARE to CPU_ONLINE CPU_UP_PREPARE binds cwq->thread to the new CPU. So CPU_UP_CANCELED tries to wake up the task which is bound to the failed CPU. With this patch we don't bind cwq->thread until CPU becomes online. The first wake_up() after kthread_create() is a bit special, make a simple helper for that. Signed-off-by: Oleg Nesterov Cc: Gautham R Shenoy Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/workqueue.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index e858e93886e3..7d1ebfc1a995 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -668,15 +668,21 @@ static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) cwq->thread = p; cwq->should_stop = 0; - if (!is_single_threaded(wq)) - kthread_bind(p, cpu); - - if (is_single_threaded(wq) || cpu_online(cpu)) - wake_up_process(p); return 0; } +static void start_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) +{ + struct task_struct *p = cwq->thread; + + if (p != NULL) { + if (cpu >= 0) + kthread_bind(p, cpu); + wake_up_process(p); + } +} + struct workqueue_struct *__create_workqueue(const char *name, int singlethread, int freezeable) { @@ -702,6 +708,7 @@ struct workqueue_struct *__create_workqueue(const char *name, if (singlethread) { cwq = init_cpu_workqueue(wq, singlethread_cpu); err = create_workqueue_thread(cwq, singlethread_cpu); + start_workqueue_thread(cwq, -1); } else { mutex_lock(&workqueue_mutex); list_add(&wq->list, &workqueues); @@ -711,6 +718,7 @@ struct workqueue_struct *__create_workqueue(const char *name, if (err || !cpu_online(cpu)) continue; err = create_workqueue_thread(cwq, cpu); + start_workqueue_thread(cwq, cpu); } mutex_unlock(&workqueue_mutex); } @@ -808,12 +816,11 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, return NOTIFY_BAD; case CPU_ONLINE: - wake_up_process(cwq->thread); + start_workqueue_thread(cwq, cpu); break; case CPU_UP_CANCELED: - if (cwq->thread) - wake_up_process(cwq->thread); + start_workqueue_thread(cwq, -1); case CPU_DEAD: cleanup_workqueue_thread(cwq, cpu); break; -- 2.20.1