From 2f92092b4be1b601d635ff03c522be83b8458c28 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 24 Jun 2011 20:39:24 +0200 Subject: [107/256] workqueue-avoid-the-lock-in-cpu-dying.patch Signed-off-by: Thomas Gleixner --- kernel/workqueue.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 50e0d00..3fd5280 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -3505,6 +3505,25 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, kthread_stop(new_trustee); return NOTIFY_BAD; } + break; + case CPU_POST_DEAD: + case CPU_UP_CANCELED: + case CPU_DOWN_FAILED: + case CPU_ONLINE: + break; + case CPU_DYING: + /* + * We access this lockless. We are on the dying CPU + * and called from stomp machine. + * + * Before this, the trustee and all workers except for + * the ones which are still executing works from + * before the last CPU down must be on the cpu. After + * this, they'll all be diasporas. + */ + gcwq->flags |= GCWQ_DISASSOCIATED; + default: + goto out; } /* some are called w/ irq disabled, don't disturb irq status */ @@ -3524,16 +3543,6 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, gcwq->first_idle = new_worker; break; - case CPU_DYING: - /* - * Before this, the trustee and all workers except for - * the ones which are still executing works from - * before the last CPU down must be on the cpu. After - * this, they'll all be diasporas. - */ - gcwq->flags |= GCWQ_DISASSOCIATED; - break; - case CPU_POST_DEAD: gcwq->trustee_state = TRUSTEE_BUTCHER; /* fall through */ @@ -3567,6 +3576,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, spin_unlock_irqrestore(&gcwq->lock, flags); +out: return notifier_from_errno(0); }