Re: [RFC PATCH net-next 6/6] virtio-net: enable tx interrupt only for the final skb in the chain
On Wed, Oct 15, 2014 at 06:31:19PM +0800, Jason Wang wrote: > On 10/15/2014 06:22 PM, Michael S. Tsirkin wrote: > > On Wed, Oct 15, 2014 at 03:25:30PM +0800, Jason Wang wrote: > >> With the help of xmit_more and virtqueue_enable_cb_avail(), this patch > >> enable tx interrupt only for the final skb in the chain if > >> needed. This will help to mitigate tx interrupts. > >> > >> Cc: Rusty Russell > >> Cc: Michael S. Tsirkin > >> Signed-off-by: Jason Wang > > I think you should split xmit_more stuff out. > > No much difference but if you prefer I will do this. In fact I did it exactly like this already :) -- MST ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [RFC PATCH net-next 6/6] virtio-net: enable tx interrupt only for the final skb in the chain
On 10/15/2014 06:22 PM, Michael S. Tsirkin wrote: > On Wed, Oct 15, 2014 at 03:25:30PM +0800, Jason Wang wrote: >> With the help of xmit_more and virtqueue_enable_cb_avail(), this patch >> enable tx interrupt only for the final skb in the chain if >> needed. This will help to mitigate tx interrupts. >> >> Cc: Rusty Russell >> Cc: Michael S. Tsirkin >> Signed-off-by: Jason Wang > I think you should split xmit_more stuff out. No much difference but if you prefer I will do this. ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [RFC PATCH net-next 6/6] virtio-net: enable tx interrupt only for the final skb in the chain
On Wed, Oct 15, 2014 at 03:25:30PM +0800, Jason Wang wrote:
> With the help of xmit_more and virtqueue_enable_cb_avail(), this patch
> enable tx interrupt only for the final skb in the chain if
> needed. This will help to mitigate tx interrupts.
>
> Cc: Rusty Russell
> Cc: Michael S. Tsirkin
> Signed-off-by: Jason Wang
I think you should split xmit_more stuff out.
> ---
> drivers/net/virtio_net.c | 10 +++---
> 1 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 2afc2e2..5943f3f 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -993,12 +993,16 @@ static netdev_tx_t start_xmit(struct sk_buff *skb,
> struct net_device *dev)
> virtqueue_disable_cb(sq->vq);
> }
> }
> - } else if (virtqueue_enable_cb(sq->vq)) {
> - free_old_xmit_skbs(sq, qsize);
> }
>
> - if (__netif_subqueue_stopped(dev, qnum) || !skb->xmit_more)
> + if (__netif_subqueue_stopped(dev, qnum) || !skb->xmit_more) {
> virtqueue_kick(sq->vq);
> + if (sq->vq->num_free >= 2 +MAX_SKB_FRAGS &&
> + unlikely(virtqueue_enable_cb_avail(sq->vq))) {
> + free_old_xmit_skbs(sq, qsize);
> + virtqueue_disable_cb(sq->vq);
> + }
> + }
>
> return NETDEV_TX_OK;
> }
> --
> 1.7.1
___
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
[RFC PATCH net-next 6/6] virtio-net: enable tx interrupt only for the final skb in the chain
With the help of xmit_more and virtqueue_enable_cb_avail(), this patch
enable tx interrupt only for the final skb in the chain if
needed. This will help to mitigate tx interrupts.
Cc: Rusty Russell
Cc: Michael S. Tsirkin
Signed-off-by: Jason Wang
---
drivers/net/virtio_net.c | 10 +++---
1 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 2afc2e2..5943f3f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -993,12 +993,16 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct
net_device *dev)
virtqueue_disable_cb(sq->vq);
}
}
- } else if (virtqueue_enable_cb(sq->vq)) {
- free_old_xmit_skbs(sq, qsize);
}
- if (__netif_subqueue_stopped(dev, qnum) || !skb->xmit_more)
+ if (__netif_subqueue_stopped(dev, qnum) || !skb->xmit_more) {
virtqueue_kick(sq->vq);
+ if (sq->vq->num_free >= 2 +MAX_SKB_FRAGS &&
+ unlikely(virtqueue_enable_cb_avail(sq->vq))) {
+ free_old_xmit_skbs(sq, qsize);
+ virtqueue_disable_cb(sq->vq);
+ }
+ }
return NETDEV_TX_OK;
}
--
1.7.1
___
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
