[PATCH] io_uring: replace smp_mb() with smp_mb__after_atomic() in io_sq_thread()

[Almog Khaikin <almogkh@gmail.com>]

The IORING_SQ_NEED_WAKEUP flag is now set using atomic_or() which
implies a full barrier on some architectures but it is not required to
do so. Use the more appropriate smp_mb__after_atomic() which avoids the
extra barrier on those architectures.

Signed-off-by: Almog Khaikin <almogkh@gmail.com>
---
 fs/io_uring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 72cb2d50125c..1e7466079af7 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8229,7 +8229,7 @@ static int io_sq_thread(void *data)
 				 * Ensure the store of the wakeup flag is not
 				 * reordered with the load of the SQ tail
 				 */
-				smp_mb();
+				smp_mb__after_atomic();
 
 				if (io_sqring_entries(ctx)) {
 					needs_sched = false;

base-commit: 6f07a54a90ee98ae13b37ac358624d7cc7e57850
-- 
2.36.0