From 5db34f5e8f5271e7bd3aefff4387b054980ebc2b Mon Sep 17 00:00:00 2001
From: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Date: Wed, 5 Jan 2011 12:48:14 +0100
Subject: [PATCH] --- yaml --- r: 227286 b: refs/heads/master c:
 34b133f8e94e39ff3cf4d1c1f67f2e07cdc3d54e h: refs/heads/master v: v3

---
 [refs]                              | 2 +-
 trunk/arch/Kconfig                  | 3 +++
 trunk/arch/s390/Kconfig             | 1 +
 trunk/arch/s390/include/asm/mutex.h | 2 ++
 trunk/include/linux/mutex.h         | 4 ++++
 trunk/kernel/mutex.c                | 2 +-
 trunk/kernel/sched.c                | 3 ++-
 7 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index fbbd2d225b18..5685d2402ce9 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c03017544e3b2e60aa3c8ae451fac01595f1bf11
+refs/heads/master: 34b133f8e94e39ff3cf4d1c1f67f2e07cdc3d54e
diff --git a/trunk/arch/Kconfig b/trunk/arch/Kconfig
index 8bf0fa652eb6..f78c2be4242b 100644
--- a/trunk/arch/Kconfig
+++ b/trunk/arch/Kconfig
@@ -175,4 +175,7 @@ config HAVE_PERF_EVENTS_NMI
 config HAVE_ARCH_JUMP_LABEL
 	bool
 
+config HAVE_ARCH_MUTEX_CPU_RELAX
+	bool
+
 source "kernel/gcov/Kconfig"
diff --git a/trunk/arch/s390/Kconfig b/trunk/arch/s390/Kconfig
index 3243f7a52c72..c05d0819f562 100644
--- a/trunk/arch/s390/Kconfig
+++ b/trunk/arch/s390/Kconfig
@@ -87,6 +87,7 @@ config S390
 	select HAVE_KERNEL_LZMA
 	select HAVE_KERNEL_LZO
 	select HAVE_GET_USER_PAGES_FAST
+	select HAVE_ARCH_MUTEX_CPU_RELAX
 	select ARCH_INLINE_SPIN_TRYLOCK
 	select ARCH_INLINE_SPIN_TRYLOCK_BH
 	select ARCH_INLINE_SPIN_LOCK
diff --git a/trunk/arch/s390/include/asm/mutex.h b/trunk/arch/s390/include/asm/mutex.h
index 458c1f7fbc18..688271f5f2e4 100644
--- a/trunk/arch/s390/include/asm/mutex.h
+++ b/trunk/arch/s390/include/asm/mutex.h
@@ -7,3 +7,5 @@
  */
 
 #include <asm-generic/mutex-dec.h>
+
+#define arch_mutex_cpu_relax()	barrier()
diff --git a/trunk/include/linux/mutex.h b/trunk/include/linux/mutex.h
index f363bc8fdc74..94b48bd40dd7 100644
--- a/trunk/include/linux/mutex.h
+++ b/trunk/include/linux/mutex.h
@@ -160,4 +160,8 @@ extern int mutex_trylock(struct mutex *lock);
 extern void mutex_unlock(struct mutex *lock);
 extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
 
+#ifndef CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX
+#define arch_mutex_cpu_relax()	cpu_relax()
+#endif
+
 #endif
diff --git a/trunk/kernel/mutex.c b/trunk/kernel/mutex.c
index 200407c1502f..a5889fb28ecf 100644
--- a/trunk/kernel/mutex.c
+++ b/trunk/kernel/mutex.c
@@ -199,7 +199,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 		 * memory barriers as we'll eventually observe the right
 		 * values at the cost of a few extra spins.
 		 */
-		cpu_relax();
+		arch_mutex_cpu_relax();
 	}
 #endif
 	spin_lock_mutex(&lock->wait_lock, flags);
diff --git a/trunk/kernel/sched.c b/trunk/kernel/sched.c
index 297d1a0eedb0..fe1c6243d258 100644
--- a/trunk/kernel/sched.c
+++ b/trunk/kernel/sched.c
@@ -75,6 +75,7 @@
 
 #include <asm/tlb.h>
 #include <asm/irq_regs.h>
+#include <asm/mutex.h>
 
 #include "sched_cpupri.h"
 #include "workqueue_sched.h"
@@ -4214,7 +4215,7 @@ int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
 		if (task_thread_info(rq->curr) != owner || need_resched())
 			return 0;
 
-		cpu_relax();
+		arch_mutex_cpu_relax();
 	}
 
 	return 1;