On 2018/11/16 下午12:10, Matthew Cover wrote:
When writing packets to a descriptor associated with a combined queue, the packets should end up on that queue. Before this change all packets written to any descriptor associated with a tap interface end up on rx-0, even when the descriptor is associated with a different queue. The rx traffic can be generated by either of the following. 1. a simple tap program which spins up multiple queues and writes packets to each of the file descriptors 2. tx from a qemu vm with a tap multiqueue netdev The queue for rx traffic can be observed by either of the following (done on the hypervisor in the qemu case). 1. a simple netmap program which opens and reads from per-queue descriptors 2. configuring RPS and doing per-cpu captures with rxtxcpu Alternatively, if you printk() the return value of skb_get_rx_queue() just before each instance of netif_receive_skb() in tun.c, you will get 65535 for every skb. Calling skb_record_rx_queue() to set the rx queue to the queue_index fixes the association between descriptor and rx queue. Signed-off-by: Matthew Cover <matthew.co...@stackpath.com> --- drivers/net/tun.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index a65779c6d72f..4e306ff3501c 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1536,6 +1536,7 @@ static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile,if (!rx_batched || (!more && skb_queue_empty(queue))) {local_bh_disable(); + skb_record_rx_queue(skb, tfile->queue_index); netif_receive_skb(skb); local_bh_enable(); return; @@ -1555,8 +1556,11 @@ static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile, struct sk_buff *nskb;local_bh_disable();- while ((nskb = __skb_dequeue(&process_queue))) + while ((nskb = __skb_dequeue(&process_queue))) { + skb_record_rx_queue(nskb, tfile->queue_index); netif_receive_skb(nskb); + } + skb_record_rx_queue(skb, tfile->queue_index); netif_receive_skb(skb); local_bh_enable(); }
Thanks for the fix. Actually, there's another path which needs to be fixed as well in tun_xdp_one(). This path is used for vhost to pass a batched of packets.
