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From: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
To: linux-ia64 <linux-ia64@vger.kernel.org>,
	Linux Kernel <linux-kernel@vger.kernel.org>
Cc: Ashok Raj <ashok.raj@intel.com>,
	"Luck, Tony" <tony.luck@intel.com>, Andrew Morton <akpm@osdl.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>,
	Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Subject: [BUGFIX] [PATCH 1/2] cpu-hotplug: Fixing confliction between CPU hot-add and IPI
Date: Fri, 27 Oct 2006 10:49:53 +0000	[thread overview]
Message-ID: <87mz7ivxri.wl%takeuchi_satoru@jp.fujitsu.com> (raw)

From: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

---
Fixing the confliction between CPU hot-add and IPI.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Acked-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

Index: linux-2.6.19-rc3/arch/ia64/kernel/smp.c
=================================--- linux-2.6.19-rc3.orig/arch/ia64/kernel/smp.c	2006-10-27 18:40:47.000000000 +0900
+++ linux-2.6.19-rc3/arch/ia64/kernel/smp.c	2006-10-27 18:49:48.000000000 +0900
@@ -328,10 +328,14 @@
 smp_call_function (void (*func) (void *info), void *info, int nonatomic, int wait)
 {
 	struct call_data_struct data;
-	int cpus = num_online_cpus()-1;
+	int cpus;
 
-	if (!cpus)
+	spin_lock(&call_lock);
+	cpus = num_online_cpus() - 1;
+	if (!cpus) {
+		spin_unlock(&call_lock);
 		return 0;
+	}
 
 	/* Can deadlock when called with interrupts disabled */
 	WARN_ON(irqs_disabled());
@@ -343,8 +347,6 @@
 	if (wait)
 		atomic_set(&data.finished, 0);
 
-	spin_lock(&call_lock);
-
 	call_data = &data;
 	mb();	/* ensure store to call_data precedes setting of IPI_CALL_FUNC */
 	send_IPI_allbutself(IPI_CALL_FUNC);

             reply	other threads:[~2006-10-27 10:49 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-27 10:49 Satoru Takeuchi [this message]
2006-10-27 13:28 ` [BUGFIX] [PATCH 1/2] cpu-hotplug: Fixing confliction between KAMEZAWA Hiroyuki

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