similar to: [PATCH RFC v3 1/3] virtio_net: enable tx interrupt

On newer hosts that support delayed tx interrupts, we probably don't have much to gain from orphaning packets early. Note: this might degrade performance for hosts without event idx support. Should be addressed by the next patch. Cc: Rusty Russell <rusty at rustcorp.com.au> Cc: Michael S. Tsirkin <mst at redhat.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com>

On newer hosts that support delayed tx interrupts, we probably don't have much to gain from orphaning packets early. Note: this might degrade performance for hosts without event idx support. Should be addressed by the next patch. Cc: Rusty Russell <rusty at rustcorp.com.au> Cc: Michael S. Tsirkin <mst at redhat.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com>

On Mon, Dec 01, 2014 at 06:17:04PM +0800, Jason Wang wrote: > On newer hosts that support delayed tx interrupts, > we probably don't have much to gain from orphaning > packets early. > > Note: this might degrade performance for > hosts without event idx support. > Should be addressed by the next patch. > > Cc: Rusty Russell <rusty at rustcorp.com.au> > Cc:

On Mon, Dec 01, 2014 at 06:17:04PM +0800, Jason Wang wrote: > On newer hosts that support delayed tx interrupts, > we probably don't have much to gain from orphaning > packets early. > > Note: this might degrade performance for > hosts without event idx support. > Should be addressed by the next patch. > > Cc: Rusty Russell <rusty at rustcorp.com.au> > Cc:

On 10/15/2014 05:53 AM, Michael S. Tsirkin wrote: > On newer hosts that support delayed tx interrupts, > we probably don't have much to gain from orphaning > packets early. > > Based on patch by Jason Wang. > > Note: this will likely degrade performance for hosts without event idx > support. Various fallback options are available, including > orphaning

On Wed, Oct 15, 2014 at 03:25:29PM +0800, Jason Wang wrote: > Orphan skb in ndo_start_xmit() breaks socket accounting and packet > queuing. This in fact breaks lots of things such as pktgen and several > TCP optimizations. And also make BQL can't be implemented for > virtio-net. > > This patch tries to solve this issue by enabling tx interrupt. To > avoid introducing

On Sat, Oct 11, 2014 at 03:16:46PM +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, this means several optimization could not work well > such as TCP small

On newer hosts that support delayed tx interrupts, we probably don't have much to gain from orphaning packets early. Based on patch by Jason Wang. Note: this might degrade performance for hosts without event idx support. Should be addressed by the next patch. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 137

On newer hosts that support delayed tx interrupts, we probably don't have much to gain from orphaning packets early. Based on patch by Jason Wang. Note: this might degrade performance for hosts without event idx support. Should be addressed by the next patch. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 137

Orphan skb in ndo_start_xmit() breaks socket accounting and packet queuing. This in fact breaks lots of things such as pktgen and several TCP optimizations. And also make BQL can't be implemented for virtio-net. This patch tries to solve this issue by enabling tx interrupt. To avoid introducing extra spinlocks, a tx napi was scheduled to free those packets. More tx interrupt mitigation

Orphan skb in ndo_start_xmit() breaks socket accounting and packet queuing. This in fact breaks lots of things such as pktgen and several TCP optimizations. And also make BQL can't be implemented for virtio-net. This patch tries to solve this issue by enabling tx interrupt. To avoid introducing extra spinlocks, a tx napi was scheduled to free those packets. More tx interrupt mitigation

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 as TCP small queue and auto corking. This can lead extra low throughput of small packets stream.

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 as TCP small queue and auto corking. This can lead extra low throughput of small packets stream.

On newer hosts that support delayed tx interrupts, we probably don't have much to gain from orphaning packets early. Based on patch by Jason Wang. Note: this will likely degrade performance for hosts without event idx support. Various fallback options are available, including orphaning conditionally. Testing TBD. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

On newer hosts that support delayed tx interrupts, we probably don't have much to gain from orphaning packets early. Based on patch by Jason Wang. Note: this will likely degrade performance for hosts without event idx support. Various fallback options are available, including orphaning conditionally. Testing TBD. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

On 2014/12/1 18:17, Jason Wang wrote: > On newer hosts that support delayed tx interrupts, > we probably don't have much to gain from orphaning > packets early. > > Note: this might degrade performance for > hosts without event idx support. > Should be addressed by the next patch. > > Cc: Rusty Russell <rusty at rustcorp.com.au> > Cc: Michael S. Tsirkin

On 2014/12/1 18:17, Jason Wang wrote: > On newer hosts that support delayed tx interrupts, > we probably don't have much to gain from orphaning > packets early. > > Note: this might degrade performance for > hosts without event idx support. > Should be addressed by the next patch. > > Cc: Rusty Russell <rusty at rustcorp.com.au> > Cc: Michael S. Tsirkin

On Sun, Apr 02, 2017 at 04:10:11PM -0400, Willem de Bruijn wrote: > From: Willem de Bruijn <willemb at google.com> > > Convert virtio-net to a standard napi tx completion path. This enables > better TCP pacing using TCP small queues and increases single stream > throughput. > > The virtio-net driver currently cleans tx descriptors on transmission > of new packets in

From: Willem de Bruijn <willemb at google.com> Convert virtio-net to a standard napi tx completion path. This enables better TCP pacing using TCP small queues and increases single stream throughput. The virtio-net driver currently cleans tx descriptors on transmission of new packets in ndo_start_xmit. Latency depends on new traffic, so is unbounded. To avoid deadlock when a socket reaches

From: Willem de Bruijn <willemb at google.com> Convert virtio-net to a standard napi tx completion path. This enables better TCP pacing using TCP small queues and increases single stream throughput. The virtio-net driver currently cleans tx descriptors on transmission of new packets in ndo_start_xmit. Latency depends on new traffic, so is unbounded. To avoid deadlock when a socket reaches