| Message ID | 20231011092728.105904-22-xuanzhuo@linux.alibaba.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | virtio-net: support AF_XDP zero copy | expand |
On Wed, Oct 11, 2023 at 05:27:27PM +0800, Xuan Zhuo wrote: > If send queue sent some packets, we update the tx timeout > record to prevent the tx timeout. > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > --- > drivers/net/virtio/xsk.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c > index 7abd46bb0e3d..e605f860edb6 100644 > --- a/drivers/net/virtio/xsk.c > +++ b/drivers/net/virtio/xsk.c > @@ -274,6 +274,16 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool, > > virtnet_xsk_check_queue(sq); > > + if (stats.packets) { > + struct netdev_queue *txq; > + struct virtnet_info *vi; > + > + vi = sq->vq->vdev->priv; > + > + txq = netdev_get_tx_queue(vi->dev, sq - vi->sq); > + txq_trans_cond_update(txq); > + } > + > u64_stats_update_begin(&sq->stats.syncp); > sq->stats.packets += stats.packets; > sq->stats.bytes += stats.bytes; I don't get what this is doing. Is there some kind of race here you are trying to address? And what introduced the race? > -- > 2.32.0.3.g01195cf9f
On Thu, 12 Oct 2023 05:10:55 -0400, "Michael S. Tsirkin" <mst@redhat.com> wrote: > On Wed, Oct 11, 2023 at 05:27:27PM +0800, Xuan Zhuo wrote: > > If send queue sent some packets, we update the tx timeout > > record to prevent the tx timeout. > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > --- > > drivers/net/virtio/xsk.c | 10 ++++++++++ > > 1 file changed, 10 insertions(+) > > > > diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c > > index 7abd46bb0e3d..e605f860edb6 100644 > > --- a/drivers/net/virtio/xsk.c > > +++ b/drivers/net/virtio/xsk.c > > @@ -274,6 +274,16 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool, > > > > virtnet_xsk_check_queue(sq); > > > > + if (stats.packets) { > > + struct netdev_queue *txq; > > + struct virtnet_info *vi; > > + > > + vi = sq->vq->vdev->priv; > > + > > + txq = netdev_get_tx_queue(vi->dev, sq - vi->sq); > > + txq_trans_cond_update(txq); > > + } > > + > > u64_stats_update_begin(&sq->stats.syncp); > > sq->stats.packets += stats.packets; > > sq->stats.bytes += stats.bytes; > > I don't get what this is doing. Is there some kind of race here you > are trying to address? And what introduced the race? Because the xsk xmit shares the send queue with the kernel xmit, then when I do benchmark, the xsk will always use the send queue, so the kernel may have no chance to do xmit, the tx watchdog thinks that the send queue is hang and prints tx timeout log. So I call the txq_trans_cond_update() to tell the tx watchdog that the send queue is working. Thanks. > > > -- > > 2.32.0.3.g01195cf9f > >
On Thu, Oct 12, 2023 at 05:12:33PM +0800, Xuan Zhuo wrote: > On Thu, 12 Oct 2023 05:10:55 -0400, "Michael S. Tsirkin" <mst@redhat.com> wrote: > > On Wed, Oct 11, 2023 at 05:27:27PM +0800, Xuan Zhuo wrote: > > > If send queue sent some packets, we update the tx timeout > > > record to prevent the tx timeout. > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > > --- > > > drivers/net/virtio/xsk.c | 10 ++++++++++ > > > 1 file changed, 10 insertions(+) > > > > > > diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c > > > index 7abd46bb0e3d..e605f860edb6 100644 > > > --- a/drivers/net/virtio/xsk.c > > > +++ b/drivers/net/virtio/xsk.c > > > @@ -274,6 +274,16 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool, > > > > > > virtnet_xsk_check_queue(sq); > > > > > > + if (stats.packets) { > > > + struct netdev_queue *txq; > > > + struct virtnet_info *vi; > > > + > > > + vi = sq->vq->vdev->priv; > > > + > > > + txq = netdev_get_tx_queue(vi->dev, sq - vi->sq); > > > + txq_trans_cond_update(txq); > > > + } > > > + > > > u64_stats_update_begin(&sq->stats.syncp); > > > sq->stats.packets += stats.packets; > > > sq->stats.bytes += stats.bytes; > > > > I don't get what this is doing. Is there some kind of race here you > > are trying to address? And what introduced the race? > > > Because the xsk xmit shares the send queue with the kernel xmit, > then when I do benchmark, the xsk will always use the send queue, > so the kernel may have no chance to do xmit, the tx watchdog > thinks that the send queue is hang and prints tx timeout log. > > So I call the txq_trans_cond_update() to tell the tx watchdog > that the send queue is working. > > Thanks. Don't like this hack. So packets are stuck in queue - that's not good is it? Is ours the only driver that shares queues like this? > > > > > > -- > > > 2.32.0.3.g01195cf9f > > > >
On Thu, 12 Oct 2023 05:36:56 -0400, "Michael S. Tsirkin" <mst@redhat.com> wrote: > On Thu, Oct 12, 2023 at 05:12:33PM +0800, Xuan Zhuo wrote: > > On Thu, 12 Oct 2023 05:10:55 -0400, "Michael S. Tsirkin" <mst@redhat.com> wrote: > > > On Wed, Oct 11, 2023 at 05:27:27PM +0800, Xuan Zhuo wrote: > > > > If send queue sent some packets, we update the tx timeout > > > > record to prevent the tx timeout. > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > > > --- > > > > drivers/net/virtio/xsk.c | 10 ++++++++++ > > > > 1 file changed, 10 insertions(+) > > > > > > > > diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c > > > > index 7abd46bb0e3d..e605f860edb6 100644 > > > > --- a/drivers/net/virtio/xsk.c > > > > +++ b/drivers/net/virtio/xsk.c > > > > @@ -274,6 +274,16 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool, > > > > > > > > virtnet_xsk_check_queue(sq); > > > > > > > > + if (stats.packets) { > > > > + struct netdev_queue *txq; > > > > + struct virtnet_info *vi; > > > > + > > > > + vi = sq->vq->vdev->priv; > > > > + > > > > + txq = netdev_get_tx_queue(vi->dev, sq - vi->sq); > > > > + txq_trans_cond_update(txq); > > > > + } > > > > + > > > > u64_stats_update_begin(&sq->stats.syncp); > > > > sq->stats.packets += stats.packets; > > > > sq->stats.bytes += stats.bytes; > > > > > > I don't get what this is doing. Is there some kind of race here you > > > are trying to address? And what introduced the race? > > > > > > Because the xsk xmit shares the send queue with the kernel xmit, > > then when I do benchmark, the xsk will always use the send queue, > > so the kernel may have no chance to do xmit, the tx watchdog > > thinks that the send queue is hang and prints tx timeout log. > > > > So I call the txq_trans_cond_update() to tell the tx watchdog > > that the send queue is working. > > > > Thanks. > > Don't like this hack. > So packets are stuck in queue - that's not good is it? > Is ours the only driver that shares queues like this? NO. And txq_trans_cond_update() is called by many net drivers for the similar reason. Thanks > > > > > > > > > > -- > > > > 2.32.0.3.g01195cf9f > > > > > > >
On Thu, Oct 12, 2023 at 07:54:02PM +0800, Xuan Zhuo wrote: > On Thu, 12 Oct 2023 05:36:56 -0400, "Michael S. Tsirkin" <mst@redhat.com> wrote: > > On Thu, Oct 12, 2023 at 05:12:33PM +0800, Xuan Zhuo wrote: > > > On Thu, 12 Oct 2023 05:10:55 -0400, "Michael S. Tsirkin" <mst@redhat.com> wrote: > > > > On Wed, Oct 11, 2023 at 05:27:27PM +0800, Xuan Zhuo wrote: > > > > > If send queue sent some packets, we update the tx timeout > > > > > record to prevent the tx timeout. > > > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > > > > > --- > > > > > drivers/net/virtio/xsk.c | 10 ++++++++++ > > > > > 1 file changed, 10 insertions(+) > > > > > > > > > > diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c > > > > > index 7abd46bb0e3d..e605f860edb6 100644 > > > > > --- a/drivers/net/virtio/xsk.c > > > > > +++ b/drivers/net/virtio/xsk.c > > > > > @@ -274,6 +274,16 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool, > > > > > > > > > > virtnet_xsk_check_queue(sq); > > > > > > > > > > + if (stats.packets) { > > > > > + struct netdev_queue *txq; > > > > > + struct virtnet_info *vi; > > > > > + > > > > > + vi = sq->vq->vdev->priv; > > > > > + > > > > > + txq = netdev_get_tx_queue(vi->dev, sq - vi->sq); > > > > > + txq_trans_cond_update(txq); > > > > > + } > > > > > + > > > > > u64_stats_update_begin(&sq->stats.syncp); > > > > > sq->stats.packets += stats.packets; > > > > > sq->stats.bytes += stats.bytes; > > > > > > > > I don't get what this is doing. Is there some kind of race here you > > > > are trying to address? And what introduced the race? > > > > > > > > > Because the xsk xmit shares the send queue with the kernel xmit, > > > then when I do benchmark, the xsk will always use the send queue, > > > so the kernel may have no chance to do xmit, the tx watchdog > > > thinks that the send queue is hang and prints tx timeout log. > > > > > > So I call the txq_trans_cond_update() to tell the tx watchdog > > > that the send queue is working. > > > > > > Thanks. > > > > Don't like this hack. > > So packets are stuck in queue - that's not good is it? > > Is ours the only driver that shares queues like this? > > NO. > > And txq_trans_cond_update() is called by many net drivers for the similar reason. > > Thanks Hmm it seems you are right. OK, sorry about the noise. > > > > > > > > > > > > > > > -- > > > > > 2.32.0.3.g01195cf9f > > > > > > > > > >
diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c index 7abd46bb0e3d..e605f860edb6 100644 --- a/drivers/net/virtio/xsk.c +++ b/drivers/net/virtio/xsk.c @@ -274,6 +274,16 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool, virtnet_xsk_check_queue(sq); + if (stats.packets) { + struct netdev_queue *txq; + struct virtnet_info *vi; + + vi = sq->vq->vdev->priv; + + txq = netdev_get_tx_queue(vi->dev, sq - vi->sq); + txq_trans_cond_update(txq); + } + u64_stats_update_begin(&sq->stats.syncp); sq->stats.packets += stats.packets; sq->stats.bytes += stats.bytes;
If send queue sent some packets, we update the tx timeout record to prevent the tx timeout. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/net/virtio/xsk.c | 10 ++++++++++ 1 file changed, 10 insertions(+)