similar to: [PATCH net-next] virtio-net: rx busy polling support

Hi all: This series introduces the support for rx busy polling support. This was useful for reduing the latency for a kvm guest. Patch 1-2 introduces helpers which is used for rx busy polling. Patch 3 implement the main function. Test was done between a kvm guest and an external host. Two hosts were connected through 40gb mlx4 cards. With both busy_poll and busy_read are set to 50 in guest, 1

Hi all: This series introduces the support for rx busy polling support. This was useful for reduing the latency for a kvm guest. Patch 1-2 introduces helpers which is used for rx busy polling. Patch 3 implement the main function. Test was done between a kvm guest and an external host. Two hosts were connected through 40gb mlx4 cards. With both busy_poll and busy_read are set to 50 in guest, 1

On Wed, Jul 16, 2014 at 02:21:47PM +0800, Jason Wang wrote: > Add basic support for rx busy polling. > > Test was done between a kvm guest and an external host. Two hosts were > connected through 40gb mlx4 cards. With both busy_poll and busy_read > are set to 50 in guest, 1 byte netperf tcp_rr shows 116% improvement: > transaction rate was increased from 9151.94 to 19787.37.

On Wed, Jul 16, 2014 at 02:21:47PM +0800, Jason Wang wrote: > Add basic support for rx busy polling. > > Test was done between a kvm guest and an external host. Two hosts were > connected through 40gb mlx4 cards. With both busy_poll and busy_read > are set to 50 in guest, 1 byte netperf tcp_rr shows 116% improvement: > transaction rate was increased from 9151.94 to 19787.37.

Add basic support for rx busy polling. Test was done between a kvm guest and an external host. Two hosts were connected through 40gb mlx4 cards. With both busy_poll and busy_read are set to 50 in guest, 1 byte netperf tcp_rr shows 116% improvement: transaction rate was increased from 9151.94 to 19787.37. Cc: Rusty Russell <rusty at rustcorp.com.au> Cc: Michael S. Tsirkin <mst at

On 07/16/2014 11:51 AM, Jason Wang wrote: > Add basic support for rx busy polling. > > Test was done between a kvm guest and an external host. Two hosts were > connected through 40gb mlx4 cards. With both busy_poll and busy_read > are set to 50 in guest, 1 byte netperf tcp_rr shows 116% improvement: > transaction rate was increased from 9151.94 to 19787.37. > > Cc: Rusty

On 07/16/2014 11:51 AM, Jason Wang wrote: > Add basic support for rx busy polling. > > Test was done between a kvm guest and an external host. Two hosts were > connected through 40gb mlx4 cards. With both busy_poll and busy_read > are set to 50 in guest, 1 byte netperf tcp_rr shows 116% improvement: > transaction rate was increased from 9151.94 to 19787.37. > > Cc: Rusty

On Thursday 17 July 2014 08:25 AM, Jason Wang wrote: > On 07/16/2014 04:38 PM, Varka Bhadram wrote: >> On 07/16/2014 11:51 AM, Jason Wang wrote: >>> Add basic support for rx busy polling. >>> >>> Test was done between a kvm guest and an external host. Two hosts were >>> connected through 40gb mlx4 cards. With both busy_poll and busy_read >>>

On Thursday 17 July 2014 08:25 AM, Jason Wang wrote: > On 07/16/2014 04:38 PM, Varka Bhadram wrote: >> On 07/16/2014 11:51 AM, Jason Wang wrote: >>> Add basic support for rx busy polling. >>> >>> Test was done between a kvm guest and an external host. Two hosts were >>> connected through 40gb mlx4 cards. With both busy_poll and busy_read >>>

On 07/16/2014 04:38 PM, Varka Bhadram wrote: > On 07/16/2014 11:51 AM, Jason Wang wrote: >> Add basic support for rx busy polling. >> >> Test was done between a kvm guest and an external host. Two hosts were >> connected through 40gb mlx4 cards. With both busy_poll and busy_read >> are set to 50 in guest, 1 byte netperf tcp_rr shows 116% improvement: >>

On 07/17/2014 11:27 AM, Varka Bhadram wrote: > > On Thursday 17 July 2014 08:25 AM, Jason Wang wrote: >> On 07/16/2014 04:38 PM, Varka Bhadram wrote: >>> On 07/16/2014 11:51 AM, Jason Wang wrote: >>>> Add basic support for rx busy polling. >>>> >>>> Test was done between a kvm guest and an external host. Two hosts were >>>>

Hi all: This series introduces the support for rx busy polling support. This was useful for reduing the latency for a kvm guest. Instead of introducing new states and spinlocks, this series re-uses NAPI state to synchonrize between NAPI and busy polling. This grealy simplified the codes and reduce the overheads of spinlocks for normal NAPI fast path. Test was done between a kvm guest and an

Hi all: This series introduces the support for rx busy polling support. This was useful for reduing the latency for a kvm guest. Instead of introducing new states and spinlocks, this series re-uses NAPI state to synchonrize between NAPI and busy polling. This grealy simplified the codes and reduce the overheads of spinlocks for normal NAPI fast path. Test was done between a kvm guest and an

On Tue, 2014-07-15 at 17:41 +0800, Jason Wang wrote: > Add basic support for rx busy polling. > > 1 byte netperf tcp_rr on mlx4 shows 116% improvement: the transaction > rate was increased from 9151.94 to 19787.37. This is a misleading changelog. You forgot to describe how you allowed busy polling, as it is not 'automatic' If not, this patch adds two spinlock/unlock pairs

On 10/15/2014 06:18 PM, Michael S. Tsirkin wrote: > 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. >> >

On 10/15/2014 06:18 PM, Michael S. Tsirkin wrote: > 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. >> >

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

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> ---