Re: [PATCH rdma-next 00/10] Enable relaxed ordering for ULPs

Honggang LI
2021-04-06T02:37:58Z

On Mon, Apr 05, 2021 at 08:23:54AM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@nvidia.com>
>
> From Avihai,
>
> Relaxed Ordering is a PCIe mechanism that relaxes the strict ordering
> imposed on PCI transactions, and thus, can improve performance.
>
> Until now, relaxed ordering could be set only by user space applications
> for user MRs. The following patch series enables relaxed ordering for the
> kernel ULPs as well. Relaxed ordering is an optional capability, and as
> such, it is ignored by vendors that don't support it.
>
> The following test results show the performance improvement achieved

Did you test this patchset with CPU does not support relaxed ordering?

We observed significantly performance degradation when run perftest with
relaxed ordering enabled over old CPU.

https://github.com/linux-rdma/perftest/issues/116

thanks