From bb980c68d323a2128a402e14d05385bd6d7c9a8a Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Tue, 17 Jul 2012 12:39:26 -0700
Subject: [PATCH] --- yaml --- r: 316716 b: refs/heads/master c:
 6575820221f7a4dd6eadecf7bf83cdd154335eda h: refs/heads/master v: v3

---
 [refs]                    |  2 +-
 trunk/include/linux/cpu.h |  5 +++--
 trunk/kernel/workqueue.c  | 38 +++++++++++++++++++++++++++++++++++++-
 3 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index 693b3e7bbbd1..e122f3e1b060 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3270476a6c0ce322354df8679652f060d66526dc
+refs/heads/master: 6575820221f7a4dd6eadecf7bf83cdd154335eda
diff --git a/trunk/include/linux/cpu.h b/trunk/include/linux/cpu.h
index 2e9b9ebbeb78..ce7a074f2519 100644
--- a/trunk/include/linux/cpu.h
+++ b/trunk/include/linux/cpu.h
@@ -73,8 +73,9 @@ enum {
 	/* migration should happen before other stuff but after perf */
 	CPU_PRI_PERF		= 20,
 	CPU_PRI_MIGRATION	= 10,
-	/* prepare workqueues for other notifiers */
-	CPU_PRI_WORKQUEUE	= 5,
+	/* bring up workqueues before normal notifiers and down after */
+	CPU_PRI_WORKQUEUE_UP	= 5,
+	CPU_PRI_WORKQUEUE_DOWN	= -5,
 };
 
 #define CPU_ONLINE		0x0002 /* CPU (unsigned)v is up */
diff --git a/trunk/kernel/workqueue.c b/trunk/kernel/workqueue.c
index 4fa9e3552f1e..f59b7fd26e26 100644
--- a/trunk/kernel/workqueue.c
+++ b/trunk/kernel/workqueue.c
@@ -3644,6 +3644,41 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
 	return NOTIFY_BAD;
 }
 
+/*
+ * Workqueues should be brought up before normal priority CPU notifiers.
+ * This will be registered high priority CPU notifier.
+ */
+static int __devinit workqueue_cpu_up_callback(struct notifier_block *nfb,
+					       unsigned long action,
+					       void *hcpu)
+{
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_UP_PREPARE:
+	case CPU_UP_CANCELED:
+	case CPU_DOWN_FAILED:
+	case CPU_ONLINE:
+		return workqueue_cpu_callback(nfb, action, hcpu);
+	}
+	return NOTIFY_OK;
+}
+
+/*
+ * Workqueues should be brought down after normal priority CPU notifiers.
+ * This will be registered as low priority CPU notifier.
+ */
+static int __devinit workqueue_cpu_down_callback(struct notifier_block *nfb,
+						 unsigned long action,
+						 void *hcpu)
+{
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_DOWN_PREPARE:
+	case CPU_DYING:
+	case CPU_POST_DEAD:
+		return workqueue_cpu_callback(nfb, action, hcpu);
+	}
+	return NOTIFY_OK;
+}
+
 #ifdef CONFIG_SMP
 
 struct work_for_cpu {
@@ -3839,7 +3874,8 @@ static int __init init_workqueues(void)
 	unsigned int cpu;
 	int i;
 
-	cpu_notifier(workqueue_cpu_callback, CPU_PRI_WORKQUEUE);
+	cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP);
+	cpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN);
 
 	/* initialize gcwqs */
 	for_each_gcwq_cpu(cpu) {