答复: [PATCH v3 0/4] Add qemu support setting qos via ovs on ovs interface

Jinsheng Zhang (张金生)-云服务集团 zhangjl02 at inspur.com
Thu Oct 28 08:19:57 UTC 2021


Hi Yalan,
It seems that there is no output error abount inbound settings from your statistics. 100KB is short for 100 kilobytes, and 1 byte is 8 bit, therefore 100 kilobytes is 800 kilobit and is also 1024*800 bit which is 819200 bit or 800 Kbit for short. Similarly, 200 KB is equal to 1600Kbit.

From your test results, inbound.average is set to 400 KB which is 400 * 1024 * 8 bit(approximately 3.2*10^6 bits). outbound.average is set to 100 KB which is approximately 0.8*10^6 bits. Considering peek and burst is larger than average. The netperf test result is meaningful.

For the second bug mentioned, after create the ovs-net, tc rules are created. But when attach an interface to an instance, qos settings is not add to port neither in xml or tc . It is a bug, I think. I will think about fixing this.

-------
Best Regards,
Jinsheng Zhang
发件人: Yalan Zhang [mailto:yalzhang at redhat.com]
发送时间: 2021年10月27日 18:35
收件人: Jinsheng Zhang (张金生)-云服务集团
抄送: libvir-list at redhat.com; Norman Shen(申嘉童)
主题: Re: [PATCH v3 0/4] Add qemu support setting qos via ovs on ovs interface


Hi Jinsheng,

Thank you for the explanation. From the statistics above, the tc outputs for outbound matches. But I'm confused about the inbound statistics:

# virsh domiftune rhel vnet5

inbound. approximately 3.2*10^6 bits: 100

inbound.peak   : 200

inbound.burst  : 256

...

#  tc -d class show  dev vnet5

class htb 1:1 parent 1:fffe prio 0 quantum 10240 rate 819200bit ceil 1638Kbit linklayer ethernet burst 256Kb/1 mpu 0b cburst 256Kb/1 mpu 0b level 0

class htb 1:fffe root rate 1638Kbit ceil 1638Kbit linklayer ethernet burst 1499b/1 mpu 0b cburst 1499b/1 mpu 0b level 7



As the value in libvirt xml is KB, inbound.average: *100 KB* can not match with *"rate 819200bit"* in tc outputs, I supposed it should be 800Kbit. Please help to confirm.

And so does "ceil 1638Kbit" (may be it should be 1600Kbit as "inbound.peak   : 200").



I have run netperf to test the actual rate, the result is pass. 2 vm connected to the same bridge, set one vm with Qos, see test results below:

# virsh domiftune rhel vnet0
inbound.average: 400
inbound.peak   : 500
inbound.burst  : 125
inbound.floor  : 0
outbound.average: 100
outbound.peak  : 200
outbound.burst : 256

Throughput for inbound:  3.92 * 10^6bits/sec

Throughput for outbound:  0.93 * 10^6bits/sec

These patches fixed the bug [1] which closed with deferred resolution. Thank you!
And this reminds me of another ovs Qos related bug [2], which was about network.
And I tried with the scenarios in [2], there are no changes(not fixed). Just for information. :-)

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1510237
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1826168


-------
Best Regards,
Yalan Zhang
IRC: yalzhang


On Tue, Oct 26, 2021 at 3:23 PM Jinsheng Zhang (张金生)-云服务集团 <zhangjl02 at inspur.com<mailto:zhangjl02 at inspur.com>> wrote:
Hi Yalan,


1)       For inbound, we can use `ovs-vsctl list qos` and `ovs-vsctl list queue`  to check them from the openvswitch side. Values can be found in other_config.  Inbound is in kbyte when set qos with `virsh    domiftune …`, well it is in bit in ovs, Therefore, when inbound.average is set to 100, the corresponding value will be  set to 819200 in ovs.

2)       For outbound, it is in kbyte in libvirt and ingress_policing_XX in ovs interface is in kbit.

3)       Ovs use tc to set qos, so we can see output from tc command.
This patch is to unify the qos control and query on ovs ports.
The conversion explanation is added in this patch: https://listman.redhat.com/archives/libvir-list/2021-August/msg00422.html
And there are 6 following patches to fix some bugs. See https://listman.redhat.com/archives/libvir-list/2021-August/msg00423.html

-------
Best Regards,
Jinsheng Zhang

发件人: Yalan Zhang [mailto:yalzhang at redhat.com<mailto:yalzhang at redhat.com>]
发送时间: 2021年10月25日 17:54
收件人: Michal Prívozník; Jinsheng Zhang (张金生)-云服务集团
抄送: libvir-list at redhat.com<mailto:libvir-list at redhat.com>; Norman Shen(申嘉童); zhangjl02
主题: Re: [PATCH v3 0/4] Add qemu support setting qos via ovs on ovs interface

Hi Jinsheng,

I have tested the patch and have some questions, could you please help to confirm?
1) For inbound, how to check it from the openvswitch side? tc will still show the statistics, is that expected?
2) For outbound, the peak is ignored. I just can not understand the "ingress_policing_burst: 2048", how can it come from the setting "outbound.burst : 256"?
3) Is the output from tc command expected?

Test inbound:
1. start vm with setting as below:
 <interface type='bridge'>
      <source bridge='ovsbr0'/>
      <virtualport type='openvswitch'/>

<bandwidth>

        <inbound average='100' peak='200' burst='256'/>

      </bandwidth>

...

</interface>
2.

# virsh domiftune rhel vnet5

inbound.average: 100

inbound.peak   : 200

inbound.burst  : 256

inbound.floor  : 0

outbound.average: 0

outbound.peak  : 0

outbound.burst : 0

# ip l

17: vnet5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc htb master ovs-system state UNKNOWN mode DEFAULT group default qlen 1000

    link/ether fe:54:00:4d:43:5a brd ff:ff:ff:ff:ff:ff

# ovs-vsctl show interface

…...

ingress_policing_burst: 0

ingress_policing_kpkts_burst: 0

ingress_policing_kpkts_rate: 0

ingress_policing_rate: 0

…...

name                : vnet5


#  tc -d class show  dev vnet5

class htb 1:1 parent 1:fffe prio 0 quantum 10240 rate 819200bit ceil 1638Kbit linklayer ethernet burst 256Kb/1 mpu 0b cburst 256Kb/1 mpu 0b level 0

class htb 1:fffe root rate 1638Kbit ceil 1638Kbit linklayer ethernet burst 1499b/1 mpu 0b cburst 1499b/1 mpu 0b level 7

#  tc -d filter show dev vnet5 parent ffff:
(no outputs)

For outbound:

# virsh dumpxml rhel | grep /bandwidth -B2

 <bandwidth>

        <outbound average='100' peak='200' burst='256'/>

      </bandwidth>

# virsh domiftune rhel vnet9

inbound.average: 0

inbound.peak   : 0

inbound.burst  : 0

inbound.floor  : 0

outbound.average: 100

outbound.peak  : 200

outbound.burst : 256

# ovs-vsctl list interface

ingress_policing_burst: 2048

ingress_policing_kpkts_burst: 0

ingress_policing_kpkts_rate: 0

ingress_policing_rate: 800
...

# tc -d filter show dev vnet9 parent ffff:

filter protocol all pref 49 basic chain 0

filter protocol all pref 49 basic chain 0 handle 0x1

       action order 1:  police 0x1 rate 800Kbit burst 256Kb mtu 64Kb action drop/pipe overhead 0b linklayer unspec

       ref 1 bind 1

# tc -d class show  dev vnet9

(no outputs)


-------
Best Regards,
Yalan Zhang
IRC: yalzhang


On Mon, Jul 12, 2021 at 3:43 PM Michal Prívozník <mprivozn at redhat.com<mailto:mprivozn at redhat.com>> wrote:
On 7/9/21 3:31 PM, Jinsheng Zhang (张金生)-云服务集团 wrote:
> Here is my signed-off-by line
>
> Signed-off-by: zhangjl02 at inspur.com<mailto:zhangjl02 at inspur.com>
>
> Thanks again for reminding:) .

Perfect.

Reviewed-by: Michal Privoznik <mprivozn at redhat.com<mailto:mprivozn at redhat.com>>

and pushed. Congratulations on your first libvirt contribution!

Michal
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20211028/4bc1c851/attachment-0001.htm>


More information about the libvir-list mailing list