net: netdev_tx_sent_queue() small optimization

Change smp_mb() imediately following a set_bit()
with smp_mb__after_atomic().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241018052310.2612084-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 86a0b7eb9461433822996d3f6374cca8ec5a85b9..bbd30f3c5d290f323394d9f6f9b668f4d87ae042 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3517,7 +3517,7 @@ static inline void netdev_tx_sent_queue(struct netdev_queue *dev_queue,
         * because in netdev_tx_completed_queue we update the dql_completed
         * before checking the XOFF flag.
         */
-       smp_mb();
+       smp_mb__after_atomic();
 
        /* check again in case another CPU has just made room avail */
        if (unlikely(dql_avail(&dev_queue->dql) >= 0))