diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 4d20c776a4ff3..8896705ccd638 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3325,6 +3325,12 @@ static inline void netif_tx_wake_all_queues(struct net_device *dev) static __always_inline void netif_tx_stop_queue(struct netdev_queue *dev_queue) { + /* Paired with READ_ONCE() from dev_watchdog() */ + WRITE_ONCE(dev_queue->trans_start, jiffies); + + /* This barrier is paired with smp_mb() from dev_watchdog() */ + smp_mb__before_atomic(); + /* Must be an atomic op see netif_txq_try_stop() */ set_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state); } @@ -3451,6 +3457,12 @@ static inline void netdev_tx_sent_queue(struct netdev_queue *dev_queue, if (likely(dql_avail(&dev_queue->dql) >= 0)) return; + /* Paired with READ_ONCE() from dev_watchdog() */ + WRITE_ONCE(dev_queue->trans_start, jiffies); + + /* This barrier is paired with smp_mb() from dev_watchdog() */ + smp_mb__before_atomic(); + set_bit(__QUEUE_STATE_STACK_XOFF, &dev_queue->state); /* diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 2af24547a82c4..38ec18f73de43 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -512,9 +512,15 @@ static void dev_watchdog(struct timer_list *t) struct netdev_queue *txq; txq = netdev_get_tx_queue(dev, i); - trans_start = READ_ONCE(txq->trans_start); if (!netif_xmit_stopped(txq)) continue; + + /* Paired with WRITE_ONCE() + smp_mb...() in + * netdev_tx_sent_queue() and netif_tx_stop_queue(). + */ + smp_mb(); + trans_start = READ_ONCE(txq->trans_start); + if (time_after(jiffies, trans_start + dev->watchdog_timeo)) { timedout_ms = jiffies_to_msecs(jiffies - trans_start); atomic_long_inc(&txq->trans_timeout);