similar to: [PATCH] vhost-net: add time limitation for tx polling(Internet mail)

On Wed, Mar 28, 2018 at 02:37:04PM +0800, Jason Wang wrote: > > > On 2018?03?28? 12:01, haibinzhang(???) wrote: > > On 2018?03?27? 19:26, Jason wrote > > On 2018?03?27? 17:12, haibinzhang wrote: > > > > handle_tx() will delay rx for a long time when busy tx polling udp packets > > > > with short length(ie: 1byte udp payload), because setting

On 2018?03?27? 17:12, haibinzhang(???) wrote: > handle_tx() will delay rx for a long time when busy tx polling udp packets > with short length(ie: 1byte udp payload), because setting VHOST_NET_WEIGHT > takes into account only sent-bytes but no time. Interesting. Looking at vhost_can_busy_poll() it tries to poke pending vhost work and exit the busy loop if it found one. So I believe

On Tue, Apr 03, 2018 at 12:29:47PM +0000, haibinzhang(???) wrote: > > >On Tue, Apr 03, 2018 at 08:08:26AM +0000, haibinzhang wrote: > >> handle_tx will delay rx for a long time when tx busy polling udp packets > >> with small length(e.g. 1byte udp payload), because setting VHOST_NET_WEIGHT > >> takes into account only sent-bytes but no single packet length.

On Tue, Apr 03, 2018 at 08:08:26AM +0000, haibinzhang(???) wrote: > handle_tx will delay rx for a long time when tx busy polling udp packets > with small length(e.g. 1byte udp payload), because setting VHOST_NET_WEIGHT > takes into account only sent-bytes but no single packet length. > > Tests were done between two Virtual Machines using netperf(UDP_STREAM, len=1), > then

On Mon, Apr 09, 2018 at 04:09:20AM +0000, haibinzhang(???) wrote: > > > On Fri, Apr 06, 2018 at 08:22:37AM +0000, haibinzhang(???) wrote: > > > handle_tx will delay rx for tens or even hundreds of milliseconds when tx busy > > > polling udp packets with small length(e.g. 1byte udp payload), because setting > > > VHOST_NET_WEIGHT takes into account only

On Fri, Apr 06, 2018 at 08:22:37AM +0000, haibinzhang(???) wrote: > handle_tx will delay rx for tens or even hundreds of milliseconds when tx busy > polling udp packets with small length(e.g. 1byte udp payload), because setting > VHOST_NET_WEIGHT takes into account only sent-bytes but no single packet length. > > Ping-Latencies shown below were tested between two Virtual Machines

On Mon, 21 May 2018 17:04:23 +0800 Jason wrote: > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/net.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index 15d191a..de544ee 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -479,6

Similar to commit a2ac99905f1e ("vhost-net: set packet weight of tx polling to 2 * vq size"), we need a packet-based limit for handler_rx, too - elsewhere, under rx flood with small packets, tx can be delayed for a very long time, even without busypolling. The pkt limit applied to handle_rx must be the same applied by handle_tx, or we will get unfair scheduling between rx and tx. Tying

Hi: This series implement batch updating of used ring for TX. This help to reduce the cache contention on used ring. The idea is first split datacopy path from zerocopy, and do only batching for datacopy. This is because zercopy had already supported its own batching. TX PPS was increased 25.8% and Netperf TCP does not show obvious differences. The split of datapath will also be helpful for

Hi: This series implement batch updating of used ring for TX. This help to reduce the cache contention on used ring. The idea is first split datacopy path from zerocopy, and do only batching for datacopy. This is because zercopy had already supported its own batching. TX PPS was increased 25.8% and Netperf TCP does not show obvious differences. The split of datapath will also be helpful for

Hi all: We do not support XDP batching for TUN since it can only receive one packet a time from vhost_net. This series tries to remove this limitation by: - introduce a TUN specific msg_control that can hold a pointer to an array of XDP buffs - try copy and build XDP buff in vhost_net - store XDP buffs in an array and submit them once for every N packets from vhost_net - since TUN can only

> @@ -461,6 +460,7 @@ static void handle_tx(struct vhost_net *net) > struct socket *sock; > struct vhost_net_ubuf_ref *uninitialized_var(ubufs); > bool zcopy, zcopy_used; > + int i, batched = VHOST_NET_BATCH; > > mutex_lock(&vq->mutex); > sock = vq->private_data; > @@ -475,6 +475,12 @@ static void handle_tx(struct

> @@ -461,6 +460,7 @@ static void handle_tx(struct vhost_net *net) > struct socket *sock; > struct vhost_net_ubuf_ref *uninitialized_var(ubufs); > bool zcopy, zcopy_used; > + int i, batched = VHOST_NET_BATCH; > > mutex_lock(&vq->mutex); > sock = vq->private_data; > @@ -475,6 +475,12 @@ static void handle_tx(struct

From: haibinzhang(???) <haibinzhang at tencent.com> Date: Fri, 6 Apr 2018 08:22:37 +0000 > handle_tx will delay rx for tens or even hundreds of milliseconds when tx busy > polling udp packets with small length(e.g. 1byte udp payload), because setting > VHOST_NET_WEIGHT takes into account only sent-bytes but no single packet length. > > Ping-Latencies shown below were tested

From: haibinzhang(???) <haibinzhang at tencent.com> Date: Mon, 9 Apr 2018 07:22:17 +0000 > handle_tx will delay rx for tens or even hundreds of milliseconds when tx busy > polling udp packets with small length(e.g. 1byte udp payload), because setting > VHOST_NET_WEIGHT takes into account only sent-bytes but no single packet length. > > Ping-Latencies shown below were tested

Hi: This series tries to implement tx batching support for vhost. This was done by using MSG_MORE as a hint for under layer socket. The backend (e.g tap) can then batch the packets temporarily in a list and submit it all once the number of bacthed exceeds a limitation. Tests shows obvious improvement on guest pktgen over over mlx4(noqueue) on host: Mpps -+%

Hi: This series tries to implement tx batching support for vhost. This was done by using MSG_MORE as a hint for under layer socket. The backend (e.g tap) can then batch the packets temporarily in a list and submit it all once the number of bacthed exceeds a limitation. Tests shows obvious improvement on guest pktgen over over mlx4(noqueue) on host: Mpps -+%

On Mon, 21 May 2018 17:04:24 +0800 Jason wrote: > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/net.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index de544ee..4ebac76 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -485,6

Hi: This series tries to implement basic tx batched processing. This is done by prefetching descriptor indices and update used ring in a batch. This intends to speed up used ring updating and improve the cache utilization. Test shows about ~22% improvement in tx pss. Please review. Jason Wang (5): vhost: split out ring head fetching logic vhost: introduce helper to prefetch desc index

Hi: This series tries to implement basic tx batched processing. This is done by prefetching descriptor indices and update used ring in a batch. This intends to speed up used ring updating and improve the cache utilization. Test shows about ~22% improvement in tx pss. Please review. Jason Wang (5): vhost: split out ring head fetching logic vhost: introduce helper to prefetch desc index