From adc15843df234c00c1b19fd2b6c580e089b5fc07 Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Wed, 30 Apr 2008 13:38:41 +0200
Subject: [PATCH] --- yaml --- r: 95333 b: refs/heads/master c:
 fd781fa25c9e9c6fd1599df060b05e7c4ad724e5 h: refs/heads/master i:   95331:
 d0b7fdd4015078eccc26c8c0fc7ce206c332858a v: v3

---
 [refs]                            |  2 +-
 trunk/arch/s390/kernel/topology.c | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index d10f7e70a621..b194f4d31e4a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d00aa4e7d0129983fc4389c85e15a066eb4e69a9
+refs/heads/master: fd781fa25c9e9c6fd1599df060b05e7c4ad724e5
diff --git a/trunk/arch/s390/kernel/topology.c b/trunk/arch/s390/kernel/topology.c
index 0becefcf19b9..661a07217057 100644
--- a/trunk/arch/s390/kernel/topology.c
+++ b/trunk/arch/s390/kernel/topology.c
@@ -9,6 +9,7 @@
 #include <linux/device.h>
 #include <linux/bootmem.h>
 #include <linux/sched.h>
+#include <linux/kthread.h>
 #include <linux/workqueue.h>
 #include <linux/cpu.h>
 #include <linux/smp.h>
@@ -229,9 +230,20 @@ void arch_update_cpu_topology(void)
 	}
 }
 
-static void topology_work_fn(struct work_struct *work)
+static int topology_kthread(void *data)
 {
 	arch_reinit_sched_domains();
+	return 0;
+}
+
+static void topology_work_fn(struct work_struct *work)
+{
+	/* We can't call arch_reinit_sched_domains() from a multi-threaded
+	 * workqueue context since it may deadlock in case of cpu hotplug.
+	 * So we have to create a kernel thread in order to call
+	 * arch_reinit_sched_domains().
+	 */
+	kthread_run(topology_kthread, NULL, "topology_update");
 }
 
 void topology_schedule_update(void)