Re: [PATCH net] vmxnet3: use gro callback when UPT is enabled

[Ronak Doshi]

> On 3/16/23, 7:37 PM, "Yunsheng Lin" <linyunsheng@xxxxxxxxxx <mailto:linyunsheng@xxxxxxxxxx>> wrote:
> > On 2023/3/17 4:34, Jakub Kicinski wrote:
> > On Thu, 16 Mar 2023 05:21:42 +0000 Ronak Doshi wrote:
> >> Below are some sample test numbers collected by our perf team.
> >> Test socket & msg size base using only gro
> >> 1VM 14vcpu UDP stream receive 256K 256 bytes (packets/sec) 217.01 Kps 187.98 Kps -13.37%
> >> 16VM 2vcpu TCP stream send Thpt 8K 256 bytes (Gbps) 18.00 Gbps 17.02 Gbps -5.44%
> >> 1VM 14vcpu ResponseTimeMean Receive (in micro secs) 163 us 170 us -4.29%
> >
> > A bit more than I suspected, thanks for the data.
>
> Maybe we do some investigation to find out why the performace lost is more than
> suspected first.
>

I don’t think holding this patch to investigate why it takes longer in GRO is worthwhile.
That is a separate issue. UPT patches are already upstreamed to Linux and cross-ported to
relevant distros for customers to use. We need to apply this patch to avoid the performance
degradation in UPT mode as LRO is not available on UPT device.

I don’t see a functional issue with this patch. In UPT as LRO is not available, it needs to use GRO.

Thanks, 
Ronak