From: Jason Gunthorpe <jgg@ziepe.ca>
To: Christoph Hellwig <hch@infradead.org>
Cc: Yonatan Maman <ymaman@nvidia.com>,
nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org,
linux-rdma@vger.kernel.org, linux-mm@kvack.org,
herbst@redhat.com, lyude@redhat.com, dakr@redhat.com,
airlied@gmail.com, simona@ffwll.ch, leon@kernel.org,
jglisse@redhat.com, akpm@linux-foundation.org,
dri-devel@lists.freedesktop.org, apopple@nvidia.com,
bskeggs@nvidia.com, Gal Shalom <GalShalom@nvidia.com>
Subject: Re: [PATCH v1 1/4] mm/hmm: HMM API for P2P DMA to device zone pages
Date: Thu, 17 Oct 2024 10:46:44 -0300 [thread overview]
Message-ID: <20241017134644.GA948948@ziepe.ca> (raw)
In-Reply-To: <ZxENV_EppCYIXfOW@infradead.org>
On Thu, Oct 17, 2024 at 06:12:55AM -0700, Christoph Hellwig wrote:
> On Thu, Oct 17, 2024 at 10:05:39AM -0300, Jason Gunthorpe wrote:
> > Broadly I think whatever flow NVMe uses for P2P will apply to ODP as
> > well.
>
> ODP is a lot simpler than NVMe for P2P actually :(
What is your thinking there? I'm looking at the latest patches and I
would expect dma_iova_init() to accept a phys so it can call
pci_p2pdma_map_type() once for the whole transaction. It is a slow
operation.
Based on the result of pci_p2pdma_map_type() it would have to take one
of three paths: direct, iommu, or acs/switch.
It feels like dma_map_page() should become a new function that takes
in the state and then it can do direct or acs based on the type held
in the state.
ODP would have to refresh the state for each page, but could follow
the same code structure.
Jason
next prev parent reply other threads:[~2024-10-17 13:46 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-15 15:23 [PATCH v1 0/4] GPU Direct RDMA (P2P DMA) for Device Private Pages Yonatan Maman
2024-10-15 15:23 ` [PATCH v1 1/4] mm/hmm: HMM API for P2P DMA to device zone pages Yonatan Maman
2024-10-16 4:49 ` Christoph Hellwig
2024-10-16 15:04 ` Yonatan Maman
2024-10-16 15:44 ` Jason Gunthorpe
2024-10-16 16:41 ` Christoph Hellwig
2024-10-16 17:44 ` Jason Gunthorpe
2024-10-17 11:58 ` Christoph Hellwig
2024-10-17 13:05 ` Jason Gunthorpe
2024-10-17 13:12 ` Christoph Hellwig
2024-10-17 13:46 ` Jason Gunthorpe [this message]
2024-10-17 13:49 ` Christoph Hellwig
2024-10-17 14:05 ` Jason Gunthorpe
2024-10-17 14:19 ` Christoph Hellwig
2024-10-16 5:10 ` Alistair Popple
2024-10-16 15:45 ` Jason Gunthorpe
2024-10-17 1:58 ` Alistair Popple
2024-10-17 11:53 ` Jason Gunthorpe
2024-10-15 15:23 ` [PATCH v1 2/4] nouveau/dmem: HMM P2P DMA for private dev pages Yonatan Maman
2024-10-16 5:12 ` Alistair Popple
2024-10-16 15:18 ` Yonatan Maman
2024-10-15 15:23 ` [PATCH v1 3/4] IB/core: P2P DMA for device private pages Yonatan Maman
2024-10-15 15:23 ` [PATCH v1 4/4] RDMA/mlx5: Enabling ATS for ODP memory Yonatan Maman
2024-10-16 4:23 ` [PATCH v1 0/4] GPU Direct RDMA (P2P DMA) for Device Private Pages Christoph Hellwig
2024-10-16 15:16 ` Yonatan Maman
2024-10-16 22:22 ` Alistair Popple
2024-10-18 7:26 ` Zhu Yanjun
2024-10-20 15:26 ` Yonatan Maman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20241017134644.GA948948@ziepe.ca \
--to=jgg@ziepe.ca \
--cc=GalShalom@nvidia.com \
--cc=airlied@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=apopple@nvidia.com \
--cc=bskeggs@nvidia.com \
--cc=dakr@redhat.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=hch@infradead.org \
--cc=herbst@redhat.com \
--cc=jglisse@redhat.com \
--cc=leon@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-rdma@vger.kernel.org \
--cc=lyude@redhat.com \
--cc=nouveau@lists.freedesktop.org \
--cc=simona@ffwll.ch \
--cc=ymaman@nvidia.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox