Re: [PATCH v2 rdma-next] RDMA/mlx5: Enable Relaxed Ordering by default for kernel ULPs
From: Leon Romanovsky <leon@kernel.org>
Date: 2021-06-10 07:45:01
Also in:
lkml
Subsystem:
infiniband subsystem, the rest · Maintainers:
Jason Gunthorpe, Leon Romanovsky, Linus Torvalds
On Wed, Jun 09, 2021 at 03:59:24PM +0200, Christoph Hellwig wrote:
On Wed, Jun 09, 2021 at 04:53:23PM +0300, Leon Romanovsky wrote:quoted
Sure, did you have in mind some concrete place? Or will new file in the Documentation/infiniband/ folder be good enough too?Maybe add a kerneldoc comment for the map_mr_sg() ib_device_ops method?
I hope that this hunk from the previous cover letter is good enough. Jason, do you want v3? or you can fold this into v2?
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 9423e70a881c..aaf63a6643d6 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h@@ -2468,6 +2468,13 @@ struct ib_device_ops { enum ib_uverbs_advise_mr_advice advice, u32 flags, struct ib_sge *sg_list, u32 num_sge, struct uverbs_attr_bundle *attrs); + /* + * Kernel users should universally support relaxed ordering (RO), + * as they are designed to read data only after observing the CQE + * and use the DMA API correctly. + * + * Some drivers implicitly enable RO if platform supports it. + */ int (*map_mr_sg)(struct ib_mr *mr, struct scatterlist *sg, int sg_nents, unsigned int *sg_offset); int (*check_mr_status)(struct ib_mr *mr, u32 check_mask,