[PATCH net-next RFC 0/3] virtio-net: Conditionally enable tx interrupt

2014-10-11 Thread Jason Wang
Hello all: We free old transmitted packets in ndo_start_xmit() currently, so any packet must be orphaned also there. This was used to reduce the overhead of tx interrupt to achieve better performance. But this may not work for some protocols such as TCP stream. TCP depends on the value of

[PATCH net-next RFC 2/3] vhost: support urgent descriptors

2014-10-11 Thread Jason Wang
This patches let vhost-net support urgent descriptors. For zerocopy case, two new types of length was introduced to make it work. Signed-off-by: Michael S. Tsirkin m...@redhat.com Signed-off-by: Jason Wang jasow...@redhat.com --- drivers/vhost/net.c | 43

[PATCH net-next RFC 1/3] virtio: support for urgent descriptors

2014-10-11 Thread Jason Wang
Below should be useful for some experiments Jason is doing. I thought I'd send it out for early review/feedback. event idx feature allows us to defer interrupts until a specific # of descriptors were used. Sometimes it might be useful to get an interrupt after a specific descriptor, regardless.

[PATCH net-next RFC 3/3] virtio-net: conditionally enable tx interrupt

2014-10-11 Thread Jason Wang
We free transmitted packets in ndo_start_xmit() in the past to get better performance in the past. One side effect is that skb_orphan() needs to be called in ndo_start_xmit() which makes sk_wmem_alloc not accurate in fact. For TCP protocol, this means several optimization could not work well such

Re: [PATCH net-next RFC 3/3] virtio-net: conditionally enable tx interrupt

2014-10-11 Thread Eric Dumazet
On Sat, 2014-10-11 at 15:16 +0800, Jason Wang wrote: We free transmitted packets in ndo_start_xmit() in the past to get better performance in the past. One side effect is that skb_orphan() needs to be called in ndo_start_xmit() which makes sk_wmem_alloc not accurate in fact. For TCP protocol,