[ovs-dev] 答复: [PATCH v5] Use TPACKET_V3 to accelerate veth for userspace datapath
Yi Yang (杨燚)-云服务集团
yangyi01 at inspur.com
Fri Mar 6 14:40:33 UTC 2020
After I checked some doubtable points, I think performance issue lies in tpacket_v3 kernel side implementation, so I fall back it to original one in case userspace-tso-enabled is set to true. V6 has been sent out, please review v6.
发件人: William Tu [mailto:u9012063 at gmail.com]
发送时间: 2020年2月27日 23:30
收件人: Yi Yang (杨燚)-云服务集团 <yangyi01 at inspur.com>
抄送: yang_y_yi at 126.com; yang_y_yi at 163.com; ovs-dev at openvswitch.org
主题: Re: [ovs-dev] [PATCH v5] Use TPACKET_V3 to accelerate veth for userspace datapath
On Tue, Feb 25, 2020 at 5:41 PM Yi Yang (杨燚)-云服务集团 <yangyi01 at inspur.com> wrote:
> In the same environment, but I used tap but not veth, retr number is 0
> for the case without this patch (of course, I applied Flavio's tap
> enable patch)
Right, because tap does not use the tpacket_v3 mmap packet, so it works fine.
> vagrant at ubuntu1804:~$ sudo ./run-iperf3.sh Connecting to host
> 10.15.1.3, port 5201 [ 4] local 10.15.1.2 port 54572 connected to
> 10.15.1.3 port 5201
> [ ID] Interval Transfer Bandwidth Retr Cwnd
> [ 4] 0.00-10.00 sec 12.6 GBytes 10.9 Gbits/sec 0 3.14 MBytes
> [ 4] 10.00-20.00 sec 12.8 GBytes 11.0 Gbits/sec 0 3.14 MBytes
> [ 4] 20.00-30.00 sec 10.2 GBytes 8.76 Gbits/sec 0 3.14 MBytes
> [ 4] 30.00-40.00 sec 10.0 GBytes 8.63 Gbits/sec 0 3.14 MBytes
> [ 4] 40.00-50.00 sec 10.4 GBytes 8.94 Gbits/sec 0 3.14 MBytes
> [ 4] 50.00-60.00 sec 10.8 GBytes 9.31 Gbits/sec 0 3.14 MBytes
> - - - - - - - - - - - - - - - - - - - - - - - - -
> [ ID] Interval Transfer Bandwidth Retr
> [ 4] 0.00-60.00 sec 67.0 GBytes 9.59 Gbits/sec 0 sender
> [ 4] 0.00-60.00 sec 67.0 GBytes 9.59 Gbits/sec
> > I can see about 30% performance improvement for veth compared to
> > last recvmmsg optimization if I use TPACKET_V3, it is about 1.98
> > Gbps, but it was 1.47 Gbps before.
> > TPACKET_V3 can support TSO, it can work only if your kernel can
> > support, this has been verified on Ubuntu 18.04 5.3.0-40-generic ,
> > if you find the performance is very poor, please turn off tso for
> > veth interfces in case userspace-tso-enable is set to true.
> Do you test the performance of enabling TSO?
> Using veth (like your run-iperf3.sh) and with kernel 5.3.
> Without your patch, with TSO enabled, I can get around 6Gbps But with
> this patch, with TSO enabled, the performance drops to 1.9Gbps.
Are you investigating this issue?
More information about the dev