This patch modifies the queue_write_unlock() function to use the
new smp_store_release() function in another pending patch. It also
removes the temporary implementation of smp_load_acquire() and
smp_store_release() function in qrwlock.c.
This patch should only be merged if PeterZ's linux-arch patch patch
was merged.
Signed-off-by: Waiman Long <Waiman.Long@xxxxxx>
Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
include/asm-generic/qrwlock.h | 4 +---
kernel/locking/qrwlock.c | 34 ----------------------------------
2 files changed, 1 insertions(+), 37 deletions(-)
diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index 2b9a7b4..4d4bd04 100644
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -179,9 +179,7 @@ static inline void queue_write_unlock(struct qrwlock *lock)
/*
* Make sure that none of the critical section will be leaked out.
*/
- smp_mb__before_clear_bit();
- ACCESS_ONCE(lock->cnts.writer) = 0;
- smp_mb__after_clear_bit();
+ smp_store_release(&lock->cnts.writer, 0)
}
/*
diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c
index 1b3ffb2..3d3ba2b 100644
--- a/kernel/locking/qrwlock.c
+++ b/kernel/locking/qrwlock.c
@@ -48,40 +48,6 @@
# define arch_mutex_cpu_relax() cpu_relax()
#endif
-#ifndef smp_load_acquire
-# ifdef CONFIG_X86
-# define smp_load_acquire(p) \
- ({ \
- typeof(*p) ___p1 = ACCESS_ONCE(*p); \
- barrier(); \
- ___p1; \
- })
-# else
-# define smp_load_acquire(p) \
- ({ \
- typeof(*p) ___p1 = ACCESS_ONCE(*p); \
- smp_mb(); \
- ___p1; \
- })
-# endif
-#endif
-
-#ifndef smp_store_release
-# ifdef CONFIG_X86
-# define smp_store_release(p, v) \
- do { \
- barrier(); \
- ACCESS_ONCE(*p) = v; \
- } while (0)
-# else
-# define smp_store_release(p, v) \
- do { \
- smp_mb(); \
- ACCESS_ONCE(*p) = v; \
- } while (0)
-# endif
-#endif
-
/*
* If an xadd (exchange-add) macro isn't available, simulate one with
* the atomic_add_return() function.
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-arch" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
