---

yaml
---
r: 269551
b: refs/heads/master
c: c576a3e
h: refs/heads/master
i:
  269549: f9c7946
  269547: cbb22be
  269543: c42d758
  269535: d4e78d3
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 84eb950db13ca40a0572ce9957e14723500943d6
+refs/heads/master: c576a3ea905c25d50339503e0e5c7fef724e0147

trunk/arch/x86/include/asm/spinlock.h

@@ -57,21 +57,21 @@
 #if (NR_CPUS < 256)
 static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock)
 {
-	unsigned short inc = 1 << TICKET_SHIFT;
-
-	asm volatile (
-		LOCK_PREFIX "xaddw %w0, %1\n"
-		"1:\t"
-		"cmpb %h0, %b0\n\t"
-		"je 2f\n\t"
-		"rep ; nop\n\t"
-		"movb %1, %b0\n\t"
-		/* don't need lfence here, because loads are in-order */
-		"jmp 1b\n"
-		"2:"
-		: "+Q" (inc), "+m" (lock->slock)
-		:
-		: "memory", "cc");
+	register union {
+		struct __raw_tickets tickets;
+		unsigned short slock;
+	} inc = { .slock = 1 << TICKET_SHIFT };
+
+	asm volatile (LOCK_PREFIX "xaddw %w0, %1\n"
+		      : "+Q" (inc), "+m" (lock->slock) : : "memory", "cc");
+
+	for (;;) {
+		if (inc.tickets.head == inc.tickets.tail)
+			break;
+		cpu_relax();
+		inc.tickets.head = ACCESS_ONCE(lock->tickets.head);
+	}
+	barrier();		/* make sure nothing creeps before the lock is taken */
 }
 
 static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock)
@@ -104,22 +104,22 @@ static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock)
 static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock)
 {
 	unsigned inc = 1 << TICKET_SHIFT;
-	unsigned tmp;
+	__ticket_t tmp;
 
-	asm volatile(LOCK_PREFIX "xaddl %0, %1\n"
-		     "movzwl %w0, %2\n\t"
-		     "shrl $16, %0\n\t"
-		     "1:\t"
-		     "cmpl %0, %2\n\t"
-		     "je 2f\n\t"
-		     "rep ; nop\n\t"
-		     "movzwl %1, %2\n\t"
-		     /* don't need lfence here, because loads are in-order */
-		     "jmp 1b\n"
-		     "2:"
-		     : "+r" (inc), "+m" (lock->slock), "=&r" (tmp)
-		     :
-		     : "memory", "cc");
+	asm volatile(LOCK_PREFIX "xaddl %0, %1\n\t"
+		     : "+r" (inc), "+m" (lock->slock)
+		     : : "memory", "cc");
+
+	tmp = inc;
+	inc >>= TICKET_SHIFT;
+
+	for (;;) {
+		if ((__ticket_t)inc == tmp)
+			break;
+		cpu_relax();
+		tmp = ACCESS_ONCE(lock->tickets.head);
+	}
+	barrier();		/* make sure nothing creeps before the lock is taken */
 }
 
 static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock)