* Re: [PATCH net-next v7] vhost_net: avoid tx queue stuck when sendmsg fails
[not found] <1610685980-38608-1-git-send-email-wangyunjian@huawei.com>
@ 2021-01-15 6:05 ` Jason Wang
2021-01-15 18:15 ` Willem de Bruijn
2021-01-19 9:55 ` Michael S. Tsirkin
[not found] ` <20210118143329.08cc14a6@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
2 siblings, 1 reply; 4+ messages in thread
From: Jason Wang @ 2021-01-15 6:05 UTC (permalink / raw)
To: wangyunjian, netdev
Cc: willemdebruijn.kernel, mst, jerry.lilijun, virtualization,
chenchanghu, brian.huangbin, xudingke
On 2021/1/15 下午12:46, wangyunjian wrote:
> From: Yunjian Wang <wangyunjian@huawei.com>
>
> Currently the driver doesn't drop a packet which can't be sent by tun
> (e.g bad packet). In this case, the driver will always process the
> same packet lead to the tx queue stuck.
>
> To fix this issue:
> 1. in the case of persistent failure (e.g bad packet), the driver
> can skip this descriptor by ignoring the error.
> 2. in the case of transient failure (e.g -ENOBUFS, -EAGAIN and -ENOMEM),
> the driver schedules the worker to try again.
>
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Jason Wang <jasowang@redhat.com>
> ---
> v7:
> * code rebase
> v6:
> * update code styles and commit log
> ---
> drivers/vhost/net.c | 26 ++++++++++++++------------
> 1 file changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index 3b744031ec8f..df82b124170e 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -828,14 +828,15 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
> msg.msg_flags &= ~MSG_MORE;
> }
>
> - /* TODO: Check specific error and bomb out unless ENOBUFS? */
> err = sock->ops->sendmsg(sock, &msg, len);
> if (unlikely(err < 0)) {
> - vhost_discard_vq_desc(vq, 1);
> - vhost_net_enable_vq(net, vq);
> - break;
> - }
> - if (err != len)
> + if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) {
> + vhost_discard_vq_desc(vq, 1);
> + vhost_net_enable_vq(net, vq);
> + break;
> + }
> + pr_debug("Fail to send packet: err %d", err);
> + } else if (unlikely(err != len))
> pr_debug("Truncated TX packet: len %d != %zd\n",
> err, len);
> done:
> @@ -924,7 +925,6 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
> msg.msg_flags &= ~MSG_MORE;
> }
>
> - /* TODO: Check specific error and bomb out unless ENOBUFS? */
> err = sock->ops->sendmsg(sock, &msg, len);
> if (unlikely(err < 0)) {
> if (zcopy_used) {
> @@ -933,11 +933,13 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
> nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
> % UIO_MAXIOV;
> }
> - vhost_discard_vq_desc(vq, 1);
> - vhost_net_enable_vq(net, vq);
> - break;
> - }
> - if (err != len)
> + if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) {
> + vhost_discard_vq_desc(vq, 1);
> + vhost_net_enable_vq(net, vq);
> + break;
> + }
> + pr_debug("Fail to send packet: err %d", err);
> + } else if (unlikely(err != len))
> pr_debug("Truncated TX packet: "
> " len %d != %zd\n", err, len);
> if (!zcopy_used)
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH net-next v7] vhost_net: avoid tx queue stuck when sendmsg fails
[not found] <1610685980-38608-1-git-send-email-wangyunjian@huawei.com>
2021-01-15 6:05 ` [PATCH net-next v7] vhost_net: avoid tx queue stuck when sendmsg fails Jason Wang
@ 2021-01-19 9:55 ` Michael S. Tsirkin
[not found] ` <20210118143329.08cc14a6@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
2 siblings, 0 replies; 4+ messages in thread
From: Michael S. Tsirkin @ 2021-01-19 9:55 UTC (permalink / raw)
To: wangyunjian
Cc: willemdebruijn.kernel, netdev, jerry.lilijun, virtualization,
xudingke, brian.huangbin, chenchanghu
On Fri, Jan 15, 2021 at 12:46:20PM +0800, wangyunjian wrote:
> From: Yunjian Wang <wangyunjian@huawei.com>
>
> Currently the driver doesn't drop a packet which can't be sent by tun
> (e.g bad packet). In this case, the driver will always process the
> same packet lead to the tx queue stuck.
>
> To fix this issue:
> 1. in the case of persistent failure (e.g bad packet), the driver
> can skip this descriptor by ignoring the error.
> 2. in the case of transient failure (e.g -ENOBUFS, -EAGAIN and -ENOMEM),
> the driver schedules the worker to try again.
>
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> v7:
> * code rebase
> v6:
> * update code styles and commit log
> ---
> drivers/vhost/net.c | 26 ++++++++++++++------------
> 1 file changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index 3b744031ec8f..df82b124170e 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -828,14 +828,15 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
> msg.msg_flags &= ~MSG_MORE;
> }
>
> - /* TODO: Check specific error and bomb out unless ENOBUFS? */
> err = sock->ops->sendmsg(sock, &msg, len);
> if (unlikely(err < 0)) {
> - vhost_discard_vq_desc(vq, 1);
> - vhost_net_enable_vq(net, vq);
> - break;
> - }
> - if (err != len)
> + if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) {
> + vhost_discard_vq_desc(vq, 1);
> + vhost_net_enable_vq(net, vq);
> + break;
> + }
> + pr_debug("Fail to send packet: err %d", err);
> + } else if (unlikely(err != len))
> pr_debug("Truncated TX packet: len %d != %zd\n",
> err, len);
> done:
> @@ -924,7 +925,6 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
> msg.msg_flags &= ~MSG_MORE;
> }
>
> - /* TODO: Check specific error and bomb out unless ENOBUFS? */
> err = sock->ops->sendmsg(sock, &msg, len);
> if (unlikely(err < 0)) {
> if (zcopy_used) {
> @@ -933,11 +933,13 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
> nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
> % UIO_MAXIOV;
> }
> - vhost_discard_vq_desc(vq, 1);
> - vhost_net_enable_vq(net, vq);
> - break;
> - }
> - if (err != len)
> + if (err == -EAGAIN || err == -ENOMEM || err == -ENOBUFS) {
> + vhost_discard_vq_desc(vq, 1);
> + vhost_net_enable_vq(net, vq);
> + break;
> + }
> + pr_debug("Fail to send packet: err %d", err);
> + } else if (unlikely(err != len))
> pr_debug("Truncated TX packet: "
> " len %d != %zd\n", err, len);
> if (!zcopy_used)
> --
> 2.23.0
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^ permalink raw reply [flat|nested] 4+ messages in thread