Messages in this thread Patch in this message | | | From | Wang Jian <> | Date | Thu, 16 Aug 2018 21:01:27 +0800 | Subject | [PATCH 1/1] tap: comment fix |
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The tap_queue and the "tap_dev" are loosely coupled, not "macvlan_dev".
And I also change one rcu_read_lock's place, seems can reduce rcu critical section a little.
Signed-off-by: Wang Jian <jianjian.wang1@gmail.com> --- drivers/net/tap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/tap.c b/drivers/net/tap.c index f0f7cd9..e5e5a8e 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -125,7 +125,7 @@ static struct tap_dev *tap_dev_get_rcu(const struct net_device *dev)
/* * RCU usage: - * The tap_queue and the macvlan_dev are loosely coupled, the + * The tap_queue and the tap_dev are loosely coupled, the * pointers from one to the other can only be read while rcu_read_lock * or rtnl is held. * @@ -720,8 +720,6 @@ static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m, __vlan_get_protocol(skb, skb->protocol, &depth) != 0) skb_set_network_header(skb, depth);
- rcu_read_lock(); - tap = rcu_dereference(q->tap); /* copy skb_ubuf_info for callback when skb has no error */ if (zerocopy) { skb_shinfo(skb)->destructor_arg = m->msg_control; @@ -732,6 +730,8 @@ static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m, uarg->callback(uarg, false); }
+ rcu_read_lock(); + tap = rcu_dereference(q->tap); if (tap) { skb->dev = tap->dev; dev_queue_xmit(skb); -- Regards, Wang Jian
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