From: Jason Gunthorpe <jgg@ziepe.ca>
To: Leon Romanovsky <leon@kernel.org>
Cc: "Mike Rapoport (Microsoft)" <rppt@kernel.org>,
linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH rdma-next] RDMA/mlx5: Make sure that UMR page is aligned to PAGE_SIZE
Date: Fri, 7 Aug 2026 20:10:38 -0300 [thread overview]
Message-ID: <20260807231038.GL200537@ziepe.ca> (raw)
In-Reply-To: <20260723083555.GD110966@unreal>
On Thu, Jul 23, 2026 at 11:35:55AM +0300, Leon Romanovsky wrote:
> On Wed, Jul 22, 2026 at 04:41:03PM -0300, Jason Gunthorpe wrote:
> > On Wed, Jul 22, 2026 at 02:41:13PM +0300, Leon Romanovsky wrote:
> > > From: Leon Romanovsky <leonro@nvidia.com>
> > >
> > > The UMR XLT buffer needs to be aligned to PAGE_SIZE.
> >
> > Why? It goes into a sgl? The device certainly does not work on
> > PAGE_SIZE, so if there is some alignment here it should be the MLX5
> > adaptor alignment
>
> We need an alignment to 2Kb as a minimum here.
>
> In our case, we got the following assert:
> ‘mlx5_post_send_umr: assertion failed (MLX5_GET64(umr_pointer_desc_argument, data, address) & 0×7ff == 0)’
So use that value, or the adaptor page size
There is no reason to align this to 64k if we need a 2k only.
Jason
next prev parent reply other threads:[~2026-08-07 23:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-22 11:41 [PATCH rdma-next] RDMA/mlx5: Make sure that UMR page is aligned to PAGE_SIZE Leon Romanovsky
2026-07-22 19:41 ` Jason Gunthorpe
2026-07-23 8:35 ` Leon Romanovsky
2026-08-07 23:10 ` Jason Gunthorpe [this message]
2026-07-27 6:22 ` Leon Romanovsky
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