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 <[email protected]> Reviewed-by: Paul E. McKenney <[email protected]> --- 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-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
