Re: [PATCH for-next 1/8] RDMA/erdma: Probe the erdma RoCEv2 device

Cheng Xu
2024-11-28T02:07:52Z

On 11/26/24 11:36 PM, Zhu Yanjun wrote:
> 在 2024/11/26 7:59, Boshi Yu 写道:
>> Currently, the erdma driver supports both the iWARP and RoCEv2 protocols.
>> The erdma driver reads the ERDMA_REGS_DEV_PROTO_REG register to identify
>> the protocol used by the erdma device. Since each protocol requires
>> different ib_device_ops, we introduce the erdma_device_ops_iwarp and
>> erdma_device_ops_rocev2 for iWARP and RoCEv2 protocols, respectively.
>>
> Hi, Boshi
>
> From alomost all of the RDMA users, it seems that RoCEv2 protocol is required while very few users request iWARP protocol in their production hosts. But in the erdma HW/FW, this iWARP protocol is supported. Is this iWARP protocol for some special use cases in the Ali-Cloud environment?
>

Hi, Yanjun,

iWarp & TCP have some good features, such as Tail Loss Probe(TLP), selective ACK and
out-of-order DDP, so that can get better performance in large-scale lossy network. The
current usage scenarios include HPC industrial simulation, redis, PolarDB and big data
in public cloud environment.

Thanks,
Cheng Xu

> I am just curious about this, not to be against this patch series. If this is related with the Ali-Cloud security, you can ignore this.
>
> Thanks,
> Zhu Yanjun
>