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-rw-r--r--arch/Kconfig3
-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/include/asm/mutex.h2
-rw-r--r--include/linux/mutex.h4
-rw-r--r--kernel/mutex.c2
-rw-r--r--kernel/sched.c3
6 files changed, 13 insertions, 2 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index 8bf0fa652eb6..f78c2be4242b 100644
--- a/arch/Kconfig
+++ b/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/arch/s390/Kconfig b/arch/s390/Kconfig
index 3243f7a52c72..c05d0819f562 100644
--- a/arch/s390/Kconfig
+++ b/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/arch/s390/include/asm/mutex.h b/arch/s390/include/asm/mutex.h
index 458c1f7fbc18..688271f5f2e4 100644
--- a/arch/s390/include/asm/mutex.h
+++ b/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/include/linux/mutex.h b/include/linux/mutex.h
index f363bc8fdc74..94b48bd40dd7 100644
--- a/include/linux/mutex.h
+++ b/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/kernel/mutex.c b/kernel/mutex.c
index 200407c1502f..a5889fb28ecf 100644
--- a/kernel/mutex.c
+++ b/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/kernel/sched.c b/kernel/sched.c
index 297d1a0eedb0..fe1c6243d258 100644
--- a/kernel/sched.c
+++ b/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;
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