this version is more efficient in the case of heavy-contention

1 files changed, 9 insertions, 4 deletions

diff --git a/include/asm-sparc64/spinlock.h b/include/asm-sparc64/spinlock.h
index abbf12b4d0..16931d4cd9 100644
--- a/include/asm-sparc64/spinlock.h
+++ b/include/asm-sparc64/spinlock.h
@@ -31,13 +31,18 @@ static inline void __raw_spin_lock(raw_spinlock_t *lock)
 "       add             %0, 1, %1 \n"
 "       cas             [%2], %0, %1 \n"
 "       cmp             %0, %1 \n"
-"       bne,a,pn        %%icc, 1b \n"
+"       be,a,pt         %%icc, 2f \n"
+"        nop \n"
+"       membar          #LoadLoad | #StoreLoad | #LoadStore\n"
+"       ba              1b\n"
 "        nop \n"
 "2:     lduw            [%3], %1 \n"
 "       cmp             %0, %1 \n"
-"       bne,a,pn        %%icc, 2b \n"
+"       be,a,pt         %%icc, 3f \n"
 "        nop \n"
-"       membar          #StoreStore | #StoreLoad"
+"       membar          #LoadLoad | #StoreLoad | #LoadStore\n"
+"       ba              2b\n"
+"3:     membar          #StoreStore | #StoreLoad"
         : "=&r" (ticket), "=&r" (tmp)
         : "r" (&lock->tail), "r" (&lock->head)
         : "memory");
@@ -80,7 +85,7 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock)
 /* We don't handle this yet, but it looks like not re-enabling the interrupts
  * works fine, too. For example, lockdep also does it like this.
  */
-#define __raw_spin_lock_flages(l, f) __raw_spin_lock(l)
+#define __raw_spin_lock_flags(l, f) __raw_spin_lock(l)