Re: [CFT] VMware vmxnet3 ethernet driver

 Bezüglich Bryan Venteicher's Nachricht vom 27.08.2013 06:18 (localtime):

...

>> It seems if_vmx doesn't support jumbo frames. If I set mtu 9000, I get
>> »vmx0: cannot populate Rx queue 0«, I have no problems using jumbo
>> frames with vmxnet3.
>>
> This could fail for two reasons - could not allocate an mbuf cluster,
> or the call to bus_dmamap_load_mbuf_sg() failed. For the former, you
> should check vmstat -z. For the later, the behavior of bus_dmamap_load_mbuf_sg()
> changed between 9.1 and 9.2, and I know it was broken for awhile. I don't
> recall exactly when I fixed it (I think shortly after I made the original
> announcement). Could you retry with the files from HEAD _at_ [1]? Also, there
> are new sysctl oids (dev.vmx.X.mbuf_load_failed & dev.vmx.X.mgetcl_failed)
> for these errors.
>
> I just compiled the driver on 9.2-RC2 with the sources from HEAD and was
> able to change the MTU to 9000.
>
> [1]- http://svnweb.freebsd.org/base/head/sys/dev/vmware/vmxnet3/

Thanks a lot for your ongoing work!
I can confirm that with recent if_vmx.c from head and compiled for
9.2-RC3, setting mtu to 9000 works as expected :-)


>> I took a oldish host (4x2,8GHz Core2[LGA775]) with recent software: ESXi
>> 5.1U1 and FreeBSD-9.2-RC2
>> Two guests are connected to one MTU9000 "VMware Software Switch".
>>
> I've got a few performance things to still look at. What's the sysctl 
> dev.vmx.X output for the if_vmx<->if_vmx tests?

Just repeated if_vmx simple iperf bench, results vary slightly from
standard 10sec run to run, but still noticable high Intr usage:

if_vmx <-> if_vmx
    1.32 GBits/sec, load: 10-45%Sys 40-48%Intr

if_vmxJumbo <-> if_vmxJumbo
    5.01 GBits/sec, load: 10-45%Sys 40-48%Intr

Please find attached the different outputs of dev.vmx.X (the mtu9000 run was only 3.47GBits/sec in that case, took the numbers anyway)

wbr,

-Harry