From: Jens Axboe <axboe@kernel.dk>
To: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
linux-block@vger.kernel.org, linux-arch@vger.kernel.org,
hch@lst.de, jmoyer@redhat.com, avi@scylladb.com
Subject: Re: [PATCH 05/15] Add io_uring IO interface
Date: Sun, 13 Jan 2019 09:22:16 -0700 [thread overview]
Message-ID: <54976aac-bef2-880f-dc10-e3030189a08a@kernel.dk> (raw)
In-Reply-To: <f97a5b9f-68f3-c4af-649d-7dffbc35e37f@kernel.dk>
On 1/11/19 11:34 AM, Jens Axboe wrote:
> On 1/11/19 11:19 AM, Martin K. Petersen wrote:
>>
>> Jens,
>>
>>> +struct io_uring_sqe {
>>> + __u8 opcode;
>>> + __u8 flags;
>>> + __u16 ioprio;
>>> + __s32 fd;
>>> + __u64 off;
>>> + union {
>>> + void *addr;
>>> + __u64 __pad;
>>> + };
>>> + __u32 len;
>>> + union {
>>> + __kernel_rwf_t rw_flags;
>>> + __u32 __resv;
>>> + };
>>> +};
>>
>> A bit tongue in cheek and yet somewhat serious: While I'm super excited
>> about the 4 x 64 bitness of the sqe, where does the integrity buffer go?
>> Or the 128-bit KV store key. How do we extend this interface beyond the
>> flags?
>
> For integrity buffers, how about we stash them on the side? The newer
> series has an extra system call, io_uring_register(), which is currently
> used for registering files and buffers for IO on the side. You could
> trivially tie an integrity buffer to an sqe through that.
>
> For KV, I thint that's an actually interesting use case (sorry,
> integrity), and we might just want to bite the bullet and extend the sqe
> to full 64 bytes. We're currently at 48 bytes, which leaves us with 16
> bytes of space for KV, and other use cases.
I bit the bullet and bumped the size. 64 bytes is a nicer size in terms
of cachelines anyway, and I really doubt that 48 vs 64 bytes makes a
size consumption problem for anyone.
The buf_index is only used for the fixed buffers, which means that we have
16 bytes / 128 bits that we can grab for things like KV.
--
Jens Axboe
next prev parent reply other threads:[~2019-01-13 16:22 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-10 2:43 [PATCHSET v2] io_uring IO interface Jens Axboe
2019-01-10 2:43 ` [PATCH 01/15] fs: add an iopoll method to struct file_operations Jens Axboe
2019-01-10 2:43 ` [PATCH 02/15] block: wire up block device iopoll method Jens Axboe
2019-01-10 2:43 ` [PATCH 03/15] block: add bio_set_polled() helper Jens Axboe
2019-01-10 2:43 ` [PATCH 04/15] iomap: wire up the iopoll method Jens Axboe
2019-01-10 2:43 ` [PATCH 05/15] Add io_uring IO interface Jens Axboe
2019-01-11 18:19 ` Martin K. Petersen
2019-01-11 18:34 ` Jens Axboe
2019-01-13 16:22 ` Jens Axboe [this message]
2019-01-15 17:31 ` Martin K. Petersen
2019-01-10 2:43 ` [PATCH 06/15] io_uring: support for IO polling Jens Axboe
2019-01-10 2:43 ` [PATCH 07/15] io_uring: add submission side request cache Jens Axboe
2019-01-10 2:43 ` [PATCH 08/15] fs: add fget_many() and fput_many() Jens Axboe
2019-01-10 2:43 ` [PATCH 09/15] io_uring: use fget/fput_many() for file references Jens Axboe
2019-01-10 2:43 ` [PATCH 10/15] io_uring: batch io_kiocb allocation Jens Axboe
2019-01-10 2:44 ` [PATCH 11/15] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2019-01-10 2:44 ` [PATCH 12/15] io_uring: add support for pre-mapped user IO buffers Jens Axboe
2019-01-10 2:44 ` [PATCH 13/15] io_uring: support kernel side submission Jens Axboe
2019-01-10 2:44 ` [PATCH 14/15] io_uring: add submission polling Jens Axboe
2019-01-10 2:44 ` [PATCH 15/15] io_uring: add io_uring_event cache hit information Jens Axboe
2019-01-10 23:12 ` Jeff Moyer
2019-01-10 23:47 ` Jens Axboe
2019-01-11 9:46 ` [PATCHSET v2] io_uring IO interface Roman Penyaev
2019-01-11 16:11 ` Ilya Dryomov
2019-01-11 16:21 ` Christoph Hellwig
2019-01-11 16:39 ` Roman Penyaev
2019-01-11 18:05 ` Jens Axboe
2019-01-16 17:49 [PATCHSET v5] " Jens Axboe
2019-01-16 17:49 ` [PATCH 05/15] Add " Jens Axboe
2019-01-17 12:02 ` Roman Penyaev
2019-01-17 13:54 ` Jens Axboe
2019-01-17 14:34 ` Roman Penyaev
2019-01-17 14:54 ` Jens Axboe
2019-01-17 15:19 ` Roman Penyaev
2019-01-17 12:48 ` Roman Penyaev
2019-01-17 14:01 ` Jens Axboe
2019-01-17 20:03 ` Jeff Moyer
2019-01-17 20:09 ` Jens Axboe
2019-01-17 20:14 ` Jens Axboe
2019-01-17 20:50 ` Jeff Moyer
2019-01-17 20:53 ` Jens Axboe
2019-01-17 21:02 ` Jeff Moyer
2019-01-17 21:17 ` Jens Axboe
2019-01-17 21:21 ` Jeff Moyer
2019-01-17 21:27 ` Jens Axboe
2019-01-18 8:23 ` Roman Penyaev
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=54976aac-bef2-880f-dc10-e3030189a08a@kernel.dk \
--to=axboe@kernel.dk \
--cc=avi@scylladb.com \
--cc=hch@lst.de \
--cc=jmoyer@redhat.com \
--cc=linux-aio@kvack.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=martin.petersen@oracle.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;
as well as URLs for NNTP newsgroup(s).