Re: [PATCH rdma-next 11/15] RDMA/mlx5: Enable relaxed ordering on Memory Window mkey on strict-RO HW

From
Jason Gunthorpe <jgg@nvidia.com>
Date
2026-08-11 19:32:03
Also in
linux-rdma, lkml
Reply to
Michael Gur, 2026-07-26
On hardware that restricts strong-ordering access for memory
registrations, set relaxed ordering on MW mkeys.
Without this change, MW allocation mkey creation fails on such HW.

Enabling RO implicitly for users in this case is acceptable since all
users share the same memory registration restriction, so any MR bound to
this MW is guaranteed to have relaxed ordering as well.
Are you sure this isn't a FW issue? With a KLM mkey what flags actually take
effect? I would expect the leaf mkey to be the one that provides the actual
in effect flags, not the MW.

If so then the FW shouldn't even be checking the ordering flags on the KLM
creations?

It is harmless either way, but it doesn't seem right.

-- 
Jason
Thread (33 messages) 33 messages, 3 authors, last reply 2026-08-11
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