Re: [PATCH rdma-next 0/3] Support out of order data placement

Jason Gunthorpe
2017-06-12T16:29:17Z

On Mon, Jun 12, 2017 at 04:19:37PM +0000, Parav Pandit wrote:

> So, - to your question - shouldn't that be a flag to disable
> out-of-order writes? By default, its disabled at RDMA level.

Bart's point is that it is not disabled, by default, it is platform
specific by default.

Your patch makes makes it more likely a ULP will see out of order
writes, but it is already the case that any ULP that relies on this is
platform specific and/or broken.

I think the answer to Bart's question is that some MPI ULPs are
'broken' and only work on x86 - setting this bit by default would
cause them to stop working. It is unfortunate this is the rare case.

I would suggest at least using the inverted sense like Bart describes
in the kernel - every kernel ULP is safe.

Jason