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-rw-r--r--include/linux/netdevice.h12
-rw-r--r--net/sched/sch_generic.c8
2 files changed, 19 insertions, 1 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 4d20c776a4ff..8896705ccd63 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 2af24547a82c..38ec18f73de4 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);