From: Daniel Gomez <da.gomez@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>, Keith Busch <kbusch@kernel.org>,
Sagi Grimberg <sagi@grimberg.me>,
Chaitanya Kulkarni <kch@nvidia.com>,
Kanchan Joshi <joshi.k@samsung.com>,
Leon Romanovsky <leon@kernel.org>,
Nitesh Shetty <nj.shetty@samsung.com>,
Logan Gunthorpe <logang@deltatee.com>,
linux-block@vger.kernel.org, linux-nvme@lists.infradead.org
Subject: Re: [PATCH 7/9] nvme-pci: convert the data mapping blk_rq_dma_map
Date: Tue, 17 Jun 2025 19:45:10 +0200 [thread overview]
Message-ID: <4e3eec2b-bd74-452f-880f-b1ad4f35bd79@kernel.org> (raw)
In-Reply-To: <edf056c9-ab8d-4b55-9e61-25a29916d55c@kernel.org>
On 17/06/2025 19.43, Daniel Gomez wrote:
> On 12/06/2025 07.02, Christoph Hellwig wrote:
>> On Wed, Jun 11, 2025 at 02:15:10PM +0200, Daniel Gomez wrote:
>>>> #define NVME_MAX_SEGS \
>>>> - min(NVME_CTRL_PAGE_SIZE / sizeof(struct nvme_sgl_desc), \
>>>> - (PAGE_SIZE / sizeof(struct scatterlist)))
>>>> + (NVME_CTRL_PAGE_SIZE / sizeof(struct nvme_sgl_desc))
>>>
>>> The 8 MiB max transfer size is only reachable if host segments are at least 32k.
>>> But I think this limitation is only on the SGL side, right?
>>
>> Yes, PRPs don't really have the concept of segments to start with.
>
> SGLs don't have the same MPS limitation we have in PRPs. So I think the correct
> calculation for NVME_MAX_SEGS is PAGE_SIZE / sizeof(struct nvme_sgl_desc).
>
Please, ignore. I forgot I already made this point.
next prev parent reply other threads:[~2025-06-17 17:45 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-10 5:06 new DMA API conversion for nvme-pci Christoph Hellwig
2025-06-10 5:06 ` [PATCH 1/9] block: don't merge different kinds of P2P transfers in a single bio Christoph Hellwig
2025-06-10 12:44 ` Leon Romanovsky
2025-06-10 15:37 ` Keith Busch
2025-06-11 3:43 ` Christoph Hellwig
2025-06-11 16:26 ` Keith Busch
2025-06-11 16:39 ` Logan Gunthorpe
2025-06-11 16:41 ` Keith Busch
2025-06-11 19:41 ` Logan Gunthorpe
2025-06-11 20:00 ` Keith Busch
2025-06-12 4:57 ` Christoph Hellwig
2025-06-12 6:24 ` Kanchan Joshi
2025-06-13 6:19 ` Christoph Hellwig
2025-06-12 15:22 ` Logan Gunthorpe
2025-06-10 5:06 ` [PATCH 2/9] block: add scatterlist-less DMA mapping helpers Christoph Hellwig
2025-06-10 12:51 ` Leon Romanovsky
2025-06-11 13:43 ` Daniel Gomez
2025-06-16 5:02 ` Christoph Hellwig
2025-06-16 6:43 ` Daniel Gomez
2025-06-16 11:31 ` Christoph Hellwig
2025-06-16 12:37 ` Daniel Gomez
2025-06-16 12:42 ` Christoph Hellwig
2025-06-16 12:52 ` Daniel Gomez
2025-06-16 13:01 ` Christoph Hellwig
2025-06-12 6:35 ` Kanchan Joshi
2025-06-13 6:17 ` Christoph Hellwig
2025-06-10 5:06 ` [PATCH 3/9] nvme-pci: simplify nvme_pci_metadata_use_sgls Christoph Hellwig
2025-06-10 12:52 ` Leon Romanovsky
2025-06-11 21:38 ` Keith Busch
2025-06-12 4:59 ` Christoph Hellwig
2025-06-10 5:06 ` [PATCH 4/9] nvme-pci: refactor nvme_pci_use_sgls Christoph Hellwig
2025-06-10 13:10 ` Leon Romanovsky
2025-06-11 13:43 ` Daniel Gomez
2025-06-12 5:00 ` Christoph Hellwig
2025-06-11 20:50 ` Keith Busch
2025-06-12 5:00 ` Christoph Hellwig
2025-06-10 5:06 ` [PATCH 5/9] nvme-pci: merge the simple PRP and SGL setup into a common helper Christoph Hellwig
2025-06-10 13:13 ` Leon Romanovsky
2025-06-11 13:44 ` Daniel Gomez
2025-06-12 5:01 ` Christoph Hellwig
2025-06-11 21:03 ` Keith Busch
2025-06-12 5:01 ` Christoph Hellwig
2025-06-10 5:06 ` [PATCH 6/9] nvme-pci: remove superfluous arguments Christoph Hellwig
2025-06-10 13:15 ` Leon Romanovsky
2025-06-11 21:05 ` Keith Busch
2025-06-10 5:06 ` [PATCH 7/9] nvme-pci: convert the data mapping blk_rq_dma_map Christoph Hellwig
2025-06-10 13:19 ` Leon Romanovsky
2025-06-11 12:15 ` Daniel Gomez
2025-06-12 5:02 ` Christoph Hellwig
2025-06-16 7:41 ` Daniel Gomez
2025-06-16 11:33 ` Christoph Hellwig
2025-06-17 17:33 ` Daniel Gomez
2025-06-17 23:25 ` Keith Busch
2025-06-17 17:43 ` Daniel Gomez
2025-06-17 17:45 ` Daniel Gomez [this message]
2025-06-11 14:13 ` Daniel Gomez
2025-06-12 5:03 ` Christoph Hellwig
2025-06-16 7:49 ` Daniel Gomez
2025-06-16 11:35 ` Christoph Hellwig
2025-06-10 5:06 ` [PATCH 8/9] nvme-pci: replace NVME_MAX_KB_SZ with NVME_MAX_BYTE Christoph Hellwig
2025-06-10 13:20 ` Leon Romanovsky
2025-06-11 14:00 ` Daniel Gomez
2025-06-10 5:06 ` [PATCH 9/9] nvme-pci: rework the build time assert for NVME_MAX_NR_DESCRIPTORS Christoph Hellwig
2025-06-10 13:21 ` Leon Romanovsky
2025-06-11 13:51 ` Daniel Gomez
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=4e3eec2b-bd74-452f-880f-b1ad4f35bd79@kernel.org \
--to=da.gomez@kernel.org \
--cc=axboe@kernel.dk \
--cc=hch@lst.de \
--cc=joshi.k@samsung.com \
--cc=kbusch@kernel.org \
--cc=kch@nvidia.com \
--cc=leon@kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-nvme@lists.infradead.org \
--cc=logang@deltatee.com \
--cc=nj.shetty@samsung.com \
--cc=sagi@grimberg.me \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.