similar to: [PATCH RFC v2 2/3] virtio_net: bql

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

On 2018/12/26 ??11:19, Michael S. Tsirkin wrote: > On Thu, Dec 06, 2018 at 04:17:36PM +0800, Jason Wang wrote: >> On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: >>> When use_napi is set, let's enable BQLs. Note: some of the issues are >>> similar to wifi. It's worth considering whether something similar to >>> commit 36148c2bbfbe ("mac80211:

On 2018/12/26 ??11:19, Michael S. Tsirkin wrote: > On Thu, Dec 06, 2018 at 04:17:36PM +0800, Jason Wang wrote: >> On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: >>> When use_napi is set, let's enable BQLs. Note: some of the issues are >>> similar to wifi. It's worth considering whether something similar to >>> commit 36148c2bbfbe ("mac80211:

On 2018/12/26 ??11:22, Michael S. Tsirkin wrote: > On Thu, Dec 06, 2018 at 04:17:36PM +0800, Jason Wang wrote: >> On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: >>> When use_napi is set, let's enable BQLs. Note: some of the issues are >>> similar to wifi. It's worth considering whether something similar to >>> commit 36148c2bbfbe ("mac80211:

On 2018/12/26 ??11:22, Michael S. Tsirkin wrote: > On Thu, Dec 06, 2018 at 04:17:36PM +0800, Jason Wang wrote: >> On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: >>> When use_napi is set, let's enable BQLs. Note: some of the issues are >>> similar to wifi. It's worth considering whether something similar to >>> commit 36148c2bbfbe ("mac80211:

On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: > When use_napi is set, let's enable BQLs. Note: some of the issues are > similar to wifi. It's worth considering whether something similar to > commit 36148c2bbfbe ("mac80211: Adjust TSQ pacing shift") might be > benefitial. I've played a similar patch several days before. The tricky part is the mode switching

On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: > When use_napi is set, let's enable BQLs. Note: some of the issues are > similar to wifi. It's worth considering whether something similar to > commit 36148c2bbfbe ("mac80211: Adjust TSQ pacing shift") might be > benefitial. I've played a similar patch several days before. The tricky part is the mode switching

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 2018/12/31 ??2:45, Michael S. Tsirkin wrote: > On Thu, Dec 27, 2018 at 06:00:36PM +0800, Jason Wang wrote: >> On 2018/12/26 ??11:19, Michael S. Tsirkin wrote: >>> On Thu, Dec 06, 2018 at 04:17:36PM +0800, Jason Wang wrote: >>>> On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: >>>>> When use_napi is set, let's enable BQLs. Note: some of the issues

On 2018/12/31 ??2:45, Michael S. Tsirkin wrote: > On Thu, Dec 27, 2018 at 06:00:36PM +0800, Jason Wang wrote: >> On 2018/12/26 ??11:19, Michael S. Tsirkin wrote: >>> On Thu, Dec 06, 2018 at 04:17:36PM +0800, Jason Wang wrote: >>>> On 2018/12/6 ??6:54, Michael S. Tsirkin wrote: >>>>> When use_napi is set, let's enable BQLs. Note: some of the issues

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

According to David, proper accounting and queueing (at all levels, not just TCP sockets) is more important than trying to skim a bunch of cycles by avoiding TX interrupts. Having an event to free the SKB is absolutely essential for the stack to operate correctly. This series tries to enable tx interrupt for virtio-net. The idea is simple: enable tx interrupt and schedule a tx napi to free old

According to David, proper accounting and queueing (at all levels, not just TCP sockets) is more important than trying to skim a bunch of cycles by avoiding TX interrupts. Having an event to free the SKB is absolutely essential for the stack to operate correctly. This series tries to enable tx interrupt for virtio-net. The idea is simple: enable tx interrupt and schedule a tx napi to free old

On Tue, Oct 14, 2014 at 02:53:27PM -0400, David Miller wrote: > From: Jason Wang <jasowang at redhat.com> > Date: Sat, 11 Oct 2014 15:16:43 +0800 > > > 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

On Tue, Oct 14, 2014 at 02:53:27PM -0400, David Miller wrote: > From: Jason Wang <jasowang at redhat.com> > Date: Sat, 11 Oct 2014 15:16:43 +0800 > > > 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

Improve tx batching using byte queue limits. Should be especially effective for MQ. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 14f4cda..b83d39d 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -227,6 +227,7 @@

Improve tx batching using byte queue limits. Should be especially effective for MQ. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 14f4cda..b83d39d 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -227,6 +227,7 @@