--- linux/include/asm-x86_64/spinlock.h.p	2007-04-01 23:49:04.000000000 -0400
+++ linux/include/asm-x86_64/spinlock.h	2007-04-02 00:34:24.000000000 -0400
@@ -19,67 +19,36 @@
 
 static inline int __raw_spin_is_locked(raw_spinlock_t *lock)
 {
-	return *(volatile signed int *)(&(lock)->slock) <= 0;
+	return unlikely(lock->qhead != lock->qtail);
 }
 
 static inline void __raw_spin_lock(raw_spinlock_t *lock)
 {
-	asm volatile(
-		"\n1:\t"
-		LOCK_PREFIX " ; decl %0\n\t"
-		"jns 2f\n"
-		"3:\n"
-		"rep;nop\n\t"
-		"cmpl $0,%0\n\t"
-		"jle 3b\n\t"
-		"jmp 1b\n"
-		"2:\t" : "=m" (lock->slock) : : "memory");
-}
+	unsigned int pos = 1;
 
-/*
- * Same as __raw_spin_lock, but reenable interrupts during spinning.
- */
-#ifndef CONFIG_PROVE_LOCKING
-static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
-{
 	asm volatile(
-		"\n1:\t"
-		LOCK_PREFIX " ; decl %0\n\t"
-		"jns 5f\n"
-		"testl $0x200, %1\n\t"	/* interrupts were disabled? */
-		"jz 4f\n\t"
-	        "sti\n"
-		"3:\t"
+		LOCK_PREFIX "xaddl %0, %1\n\t"
+		"1:\n\t"
+		"cmpl %0, %2\n\t"
+		"je 2f\n\t"
 		"rep;nop\n\t"
-		"cmpl $0, %0\n\t"
-		"jle 3b\n\t"
-		"cli\n\t"
-		"jmp 1b\n"
-		"4:\t"
-		"rep;nop\n\t"
-		"cmpl $0, %0\n\t"
-		"jg 1b\n\t"
-		"jmp 4b\n"
-		"5:\n\t"
-		: "+m" (lock->slock) : "r" ((unsigned)flags) : "memory");
+		"jmp 1b\n\t"
+		"2:\n\t"
+		     : "+r" (pos), "+m" (lock->qhead)
+		     : "m" (lock->qtail) : "memory");
 }
-#endif
+
+#define __raw_spin_lock_flags(a,b) __raw_spin_lock(a)
 
 static inline int __raw_spin_trylock(raw_spinlock_t *lock)
 {
-	int oldval;
-
-	asm volatile(
-		"xchgl %0,%1"
-		:"=q" (oldval), "=m" (lock->slock)
-		:"0" (0) : "memory");
-
-	return oldval > 0;
+	unsigned int qtail = lock->qtail;
+	return likely(cmpxchg(&lock->qhead, qtail, qtail+1) == qtail);
 }
 
 static inline void __raw_spin_unlock(raw_spinlock_t *lock)
 {
-	asm volatile("movl $1,%0" :"=m" (lock->slock) :: "memory");
+	asm volatile("addl $1,%0" :"=m" (lock->qtail) :: "memory");
 }
 
 static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
--- linux/include/asm-x86_64/spinlock_types.h.p	2007-04-01 23:49:10.000000000 -0400
+++ linux/include/asm-x86_64/spinlock_types.h	2007-04-01 23:49:21.000000000 -0400
@@ -6,10 +6,11 @@
 #endif
 
 typedef struct {
-	unsigned int slock;
+	unsigned int qhead;
+	unsigned int qtail;
 } raw_spinlock_t;
 
-#define __RAW_SPIN_LOCK_UNLOCKED	{ 1 }
+#define __RAW_SPIN_LOCK_UNLOCKED	{ 0, 0 }
 
 typedef struct {
 	unsigned int lock;