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authorMatthew Cover <werekraken@gmail.com>2018-11-18 00:46:00 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-23 08:19:26 +0100
commit453fcc4b536a6427829e0a89a41d605a2f29bc0e (patch)
tree7b12c3bdd306b150a11ed28107455739eeffd5f9 /drivers/net/tun.c
parent8e201ff7140a23ea154cad8d348d1e6e79cf0bc7 (diff)
tuntap: fix multiqueue rx
[ Upstream commit 8ebebcba559a1bfbaec7bbda64feb9870b9c58da ] 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.cover@stackpath.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 7f8c7e3aa356..0a008d136aae 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1214,6 +1214,7 @@ 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;
@@ -1233,8 +1234,11 @@ 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();
}