[PATCH 1/2] mutex: Better control mutex adaptive spinning config

From: Frederic Weisbecker
Date: Wed Dec 02 2009 - 14:49:26 EST


Introduce CONFIG_MUTEX_SPIN_ON_OWNER so that we can centralize in a
single place the conditions that determine its definition and use.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
kernel/Kconfig.locks | 3 +++
kernel/mutex.c | 4 ++--
2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks
index d1f86db..88c92fb 100644
--- a/kernel/Kconfig.locks
+++ b/kernel/Kconfig.locks
@@ -197,3 +197,6 @@ config INLINE_WRITE_UNLOCK_IRQ

config INLINE_WRITE_UNLOCK_IRQRESTORE
def_bool !DEBUG_SPINLOCK && ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
+
+config MUTEX_SPIN_ON_OWNER
+ def_bool SMP && !DEBUG_MUTEXES && !HAVE_DEFAULT_NO_SPIN_MUTEXES
diff --git a/kernel/mutex.c b/kernel/mutex.c
index 947b3ad..632f04c 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -148,8 +148,8 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,

preempt_disable();
mutex_acquire(&lock->dep_map, subclass, 0, ip);
-#if defined(CONFIG_SMP) && !defined(CONFIG_DEBUG_MUTEXES) && \
- !defined(CONFIG_HAVE_DEFAULT_NO_SPIN_MUTEXES)
+
+#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
/*
* Optimistic spinning.
*
--
1.6.2.3

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