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On Mon, 21 May 2018 17:04:25 +0800 Jason wrote: > Instead of mixing zerocopy and datacopy logics, this patch tries to > split datacopy logic out. This results for a more compact code and > specific optimization could be done on top more easily. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/net.c | 111

Instead of mixing zerocopy and datacopy logics, this patch tries to split datacopy logic out. This results for a more compact code and specific optimization could be done on top more easily. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/net.c | 111 +++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 102 insertions(+), 9 deletions(-) diff --git

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

On Fri, Jul 20, 2018 at 08:15:12AM +0800, Jason Wang wrote: > 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%

On Fri, Nov 23, 2018 at 11:00:15AM +0800, Jason Wang wrote: > This makes vhost_net to support in order feature. This is as simple as > use datacopy path when it was negotiated. An alternative is not to > advertise in order when zerocopy is enabled which tends to be > suboptimal consider zerocopy may suffer from e.g HOL issues. Well IIRC vhost_zerocopy_signal_used is used to actually

Vhost_net was known to suffer from HOL[1] issues which is not easy to fix. Several downstream disable the feature by default. What's more, the datapath was split and datacopy path got the support of batching and XDP support recently which makes it faster than zerocopy part for small packets transmission. It looks to me that disable zerocopy by default is more appropriate. It cold be enabled

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

On Fri, 03/21 17:41, Jason Wang wrote: > This patch adds simple python to display vhost satistics of vhost, the codes > were based on kvm_stat script from qemu. As work function has been recored, > filters could be used to distinguish which kinds of work are being executed or > queued: > > vhost statistics > > vhost_virtio_update_used_idx 1215215 0

On Fri, 03/21 17:41, Jason Wang wrote: > This patch adds simple python to display vhost satistics of vhost, the codes > were based on kvm_stat script from qemu. As work function has been recored, > filters could be used to distinguish which kinds of work are being executed or > queued: > > vhost statistics > > vhost_virtio_update_used_idx 1215215 0

Recent debugging on vhost net zerocopy shows the need of tracepoints. So to help in vhost{net} debugging and performance analyzing, the following series adding basic tracepoints to vhost. Operations of both vhost and vhost_net were traced in current implementation. A top-like satistics displaying script were introduced to help the troubleshooting: vhost statistics vhost_virtio_update_used_idx

Recent debugging on vhost net zerocopy shows the need of tracepoints. So to help in vhost{net} debugging and performance analyzing, the following series adding basic tracepoints to vhost. Operations of both vhost and vhost_net were traced in current implementation. A top-like satistics displaying script were introduced to help the troubleshooting: vhost statistics vhost_virtio_update_used_idx

On Mon, Sep 4, 2017 at 5:03 AM, Jason Wang <jasowang at redhat.com> wrote: > > > On 2017?09?02? 00:17, Willem de Bruijn wrote: >>>>> >>>>> This is not a 50/50 split, which impliesTw that some packets from the >>>>> large >>>>> packet flow are still converted to copying. Without the change the rate >>>>>

On Mon, Sep 4, 2017 at 5:03 AM, Jason Wang <jasowang at redhat.com> wrote: > > > On 2017?09?02? 00:17, Willem de Bruijn wrote: >>>>> >>>>> This is not a 50/50 split, which impliesTw that some packets from the >>>>> large >>>>> packet flow are still converted to copying. Without the change the rate >>>>>

Hi: This series implement basic in order feature support for vhost_net. This feature requires both driver and device to use descriptors in order which can simplify the implementation and optimizaton for both side. The series also implement a simple optimization that avoid read available ring. Test shows 10% performance improvement. More optimizations could be done on top. Jason Wang (3):

>>> This is not a 50/50 split, which impliesTw that some packets from the >>> large >>> packet flow are still converted to copying. Without the change the rate >>> without queue was 80k zerocopy vs 80k copy, so this choice of >>> (vq->num >> 2) appears too conservative. >>> >>> However, testing with (vq->num >> 1) was

>>> This is not a 50/50 split, which impliesTw that some packets from the >>> large >>> packet flow are still converted to copying. Without the change the rate >>> without queue was 80k zerocopy vs 80k copy, so this choice of >>> (vq->num >> 2) appears too conservative. >>> >>> However, testing with (vq->num >> 1) was

This patch adds simple python to display vhost satistics of vhost, the codes were based on kvm_stat script from qemu. As work function has been recored, filters could be used to distinguish which kinds of work are being executed or queued: vhost statistics vhost_virtio_update_used_idx 1215215 0 vhost_virtio_get_vq_desc 1215215 0

This makes vhost_net to support in order feature. This is as simple as use datacopy path when it was negotiated. An alternative is not to advertise in order when zerocopy is enabled which tends to be suboptimal consider zerocopy may suffer from e.g HOL issues. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/net.c | 6 ++++-- 1 file changed, 4 insertions(+), 2

From: Jason Wang <jasowang at redhat.com> [ Upstream commit 098eadce3c622c07b328d0a43dda379b38cf7c5e ] Vhost_net was known to suffer from HOL[1] issues which is not easy to fix. Several downstream disable the feature by default. What's more, the datapath was split and datacopy path got the support of batching and XDP support recently which makes it faster than zerocopy part for small