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

From: Jason Gunthorpe <[email-masked]>
Date: Tue, 6 Apr 2021 08:49:52 -0300

On Mon, Apr 05, 2021 at 11:42:31PM +0000, Chuck Lever III wrote:
 
> We need to get a better idea what correctness testing has been done,
> and whether positive correctness testing results can be replicated
> on a variety of platforms.

RO has been rolling out slowly on mlx5 over a few years and storage
ULPs are the last to change. eg the mlx5 ethernet driver has had RO
turned on for a long time, userspace HPC applications have been using
it for a while now too.

We know there are platforms with broken RO implementations (like
Haswell) but the kernel is supposed to globally turn off RO on all
those cases. I'd be a bit surprised if we discover any more from this
series.

On the other hand there are platforms that get huge speed ups from
turning this on, AMD is one example, there are a bunch in the ARM
world too.

Still, obviously people should test on the platforms they have.

Jason