65 lines
1.8 KiB
Diff
65 lines
1.8 KiB
Diff
Subject: workqueue-avoid-the-lock-in-cpu-dying.patch
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From: Thomas Gleixner <tglx@linutronix.de>
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Date: Fri, 24 Jun 2011 20:39:24 +0200
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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---
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kernel/workqueue.c | 30 ++++++++++++++++++++----------
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1 file changed, 20 insertions(+), 10 deletions(-)
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Index: linux-3.2/kernel/workqueue.c
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===================================================================
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--- linux-3.2.orig/kernel/workqueue.c
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+++ linux-3.2/kernel/workqueue.c
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@@ -3507,6 +3507,25 @@ static int __devinit workqueue_cpu_callb
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kthread_stop(new_trustee);
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return NOTIFY_BAD;
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}
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+ break;
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+ case CPU_POST_DEAD:
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+ case CPU_UP_CANCELED:
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+ case CPU_DOWN_FAILED:
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+ case CPU_ONLINE:
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+ break;
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+ case CPU_DYING:
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+ /*
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+ * We access this lockless. We are on the dying CPU
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+ * and called from stomp machine.
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+ *
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+ * Before this, the trustee and all workers except for
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+ * the ones which are still executing works from
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+ * before the last CPU down must be on the cpu. After
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+ * this, they'll all be diasporas.
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+ */
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+ gcwq->flags |= GCWQ_DISASSOCIATED;
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+ default:
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+ goto out;
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}
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/* some are called w/ irq disabled, don't disturb irq status */
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@@ -3526,16 +3545,6 @@ static int __devinit workqueue_cpu_callb
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gcwq->first_idle = new_worker;
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break;
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- case CPU_DYING:
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- /*
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- * Before this, the trustee and all workers except for
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- * the ones which are still executing works from
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- * before the last CPU down must be on the cpu. After
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- * this, they'll all be diasporas.
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- */
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- gcwq->flags |= GCWQ_DISASSOCIATED;
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- break;
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-
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case CPU_POST_DEAD:
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gcwq->trustee_state = TRUSTEE_BUTCHER;
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/* fall through */
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@@ -3569,6 +3578,7 @@ static int __devinit workqueue_cpu_callb
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spin_unlock_irqrestore(&gcwq->lock, flags);
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+out:
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return notifier_from_errno(0);
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}
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