From 8160fb43d55d26d64607fd32fe69185a5f5fe41f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 16 Nov 2021 19:29:21 -0800 Subject: [PATCH] net: use an atomic_long_t for queue->trans_timeout tx_timeout_show() assumed dev_watchdog() would stop all the queues, to fetch queue->trans_timeout under protection of the queue->_xmit_lock. As we want to no longer disrupt transmits, we use an atomic_long_t instead. Signed-off-by: Eric Dumazet Cc: david decotigny Signed-off-by: David S. Miller --- include/linux/netdevice.h | 2 +- net/core/net-sysfs.c | 6 +----- net/sched/sch_generic.c | 2 +- 3 files changed, 3 insertions(+), 7 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index dd328364dfe9..1d22483cf78c 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -592,7 +592,7 @@ struct netdev_queue { * Number of TX timeouts for this queue * (/sys/class/net/DEV/Q/trans_timeout) */ - unsigned long trans_timeout; + atomic_long_t trans_timeout; /* Subordinate device that the queue has been assigned to */ struct net_device *sb_dev; diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 9c01c642cf9e..addbef5419fb 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1201,11 +1201,7 @@ static const struct sysfs_ops netdev_queue_sysfs_ops = { static ssize_t tx_timeout_show(struct netdev_queue *queue, char *buf) { - unsigned long trans_timeout; - - spin_lock_irq(&queue->_xmit_lock); - trans_timeout = queue->trans_timeout; - spin_unlock_irq(&queue->_xmit_lock); + unsigned long trans_timeout = atomic_long_read(&queue->trans_timeout); return sprintf(buf, fmt_ulong, trans_timeout); } diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 3b0f62095803..1b4328bd495d 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -467,7 +467,7 @@ static void dev_watchdog(struct timer_list *t) time_after(jiffies, (trans_start + dev->watchdog_timeo))) { some_queue_timedout = 1; - txq->trans_timeout++; + atomic_long_inc(&txq->trans_timeout); break; } } -- 2.20.1