On Mon, 2016-05-16 at 09:17 +0800, Jason Wang wrote: > We used to queue tx packets in sk_receive_queue, this is less > efficient since it requires spinlocks to synchronize between producer > and consumer.
... > struct tun_struct *detached; > + /* reader lock */ > + spinlock_t rlock; > + unsigned long tail; > + struct tun_desc tx_descs[TUN_RING_SIZE]; > + /* writer lock */ > + spinlock_t wlock; > + unsigned long head; > }; > Ok, we had these kind of ideas floating around for many other cases, like qdisc, UDP or af_packet sockets... I believe we should have a common set of helpers, not hidden in drivers/net/tun.c but in net/core/skb_ring.c or something, with more flexibility (like the number of slots) BTW, why are you using spin_lock_irqsave() in tun_net_xmit() and tun_peek() ? BH should be disabled already (in tun_next_xmit()), and we can not transmit from hard irq. Thanks.