From: Linhaifeng <haifeng.lin@huawei•com>
To: <netdev@vger•kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat•com>,
lilijun <jerry.lilijun@huawei•com>,
"liuyongan@huawei•com" <liuyongan@huawei•com>,
"lixiao (H)" <lixiao91@huawei•com>
Subject: virtio-net: tx queue was stopped
Date: Sun, 15 Mar 2015 14:50:27 +0800 [thread overview]
Message-ID: <55052BB3.2080705@huawei.com> (raw)
Hi,Michael
I had tested the start_xmit function by the follow code found that the tx queue's state is stopped and can't send any packets anymore.
static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
{
... ...
capacity = 10; //########## test code : force to call netif_stop_queue
if (capacity < 2+MAX_SKB_FRAGS) {
netif_stop_queue(dev);
if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) {
/* More just got used, free them then recheck. */
capacity += free_old_xmit_skbs(vi);
dev_warn(&dev->dev, "free_old_xmit_skbs capacity =%d MAX_SKB_FRAGS=%d", capacity, MAX_SKB_FRAGS);
capacity = 10; //########## test code : force not to call netif_start_queue
if (capacity >= 2+MAX_SKB_FRAGS) {
netif_start_queue(dev);
virtqueue_disable_cb(vi->svq);
} else {
//########## OTOH if often enter this branch tx queue maybe stopped.
}
}
//########## Should we start queue here? I found that sometimes skb_xmit_done run before netif_stop_queue if this occurred the queue's state is
//########## stopped and have to reload virtio-net module to restore network.
}
}
ping 9.62.1.2 -i 0.1
64 bytes from 9.62.1.2: icmp_seq=19 ttl=64 time=0.115 ms
64 bytes from 9.62.1.2: icmp_seq=20 ttl=64 time=0.101 ms
64 bytes from 9.62.1.2: icmp_seq=21 ttl=64 time=0.094 ms
64 bytes from 9.62.1.2: icmp_seq=22 ttl=64 time=0.098 ms
64 bytes from 9.62.1.2: icmp_seq=23 ttl=64 time=0.097 ms
64 bytes from 9.62.1.2: icmp_seq=24 ttl=64 time=0.095 ms
64 bytes from 9.62.1.2: icmp_seq=25 ttl=64 time=0.095 ms
....
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
....
--
Regards,
Haifeng
next reply other threads:[~2015-03-15 6:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-15 6:50 Linhaifeng [this message]
2015-03-15 8:40 ` virtio-net: tx queue was stopped Michael S. Tsirkin
2015-03-16 9:24 ` Linhaifeng
2015-03-16 12:26 ` Michael S. Tsirkin
2015-03-20 9:23 ` Linhaifeng
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