linux-block.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jens Axboe <axboe@kernel.dk>
To: Marek Majkowski <marek@cloudflare.com>
Cc: Avi Kivity <avi@scylladb.com>,
	hch@lst.de, Jann Horn <jannh@google.com>,
	jmoyer@redhat.com, linux-aio@kvack.org,
	linux-api@vger.kernel.org, linux-block@vger.kernel.org,
	viro@zeniv.linux.org.uk
Subject: Re: [PATCHSET v15] io_uring IO interface
Date: Fri, 22 Feb 2019 15:32:49 -0700	[thread overview]
Message-ID: <a75ebf28-66c0-4eaf-9c76-03843ce622b6@kernel.dk> (raw)
In-Reply-To: <CAJPywTLGBRviKYSf+AQg-0eOZ3pnyTFEhr28no9Zrh8ftsSxmQ@mail.gmail.com>

On 2/22/19 8:01 AM, Marek Majkowski wrote:
> On Thu, Feb 21, 2019 at 6:48 PM Jens Axboe <axboe@kernel.dk> wrote:
>>
>> On 2/21/19 5:10 AM, Marek Majkowski wrote:
>>>> From: Jens Axboe <axboe@kernel.dk>
>>>> Subject: [PATCHSET v15] io_uring IO interface
>>>> Message-ID: <20190211190049.7888-1-axboe@kernel.dk> (raw)
>>>>
>>>> Some final tweaks, mostly cosmetic, but also two important fixes:
>>>>
>>>> 1) Ensure that we account the skb appropriately against the socket.
>>>>    Some network config options apparently return is an skb with
>>>>    ->truesize != 0 when allocated with a size of 0, ensure we add
>>>>    those as references against sock->sk_wmem_alloc. Reported by
>>>>    Matt Mullins.
>>>
>>> Jens,
>>>
>>> I tried using io_uring with network sockets. It seem to be doing the
>>> right thing. One bit is missing though: "flags" as in recv(2).
>>>
>>> In perfect world I would like to specify at least:
>>>  - MSG_DONTWAIT
>>>  - MSG_WAITALL
>>>  - MSG_NOSIGNAL
>>>
>>> Right now, unless I'm missing something, io_uring_sqe doesn't have a
>>> place where we could store these. "flags" is needed for any
>>> non-trivial network I/O.
>>
>> We have flags for sqes, depending on the type. You can add to the
>> union that already holds rw_flags/fsync_flags/poll_events? There's
>> also a (smaller) flags field that applies for all types, which
>> currently only holds the fixed file flag.
> 
> The "sqe->flags" right now is used by the IOSQE_FIXED_FILE which has
> the same value as MSG_OOB.
> 
> Sticking recv/send flags into the "rw_flags" union perhaps could work,
> barring the discussion about naming. The obvious names don't make
> sense. recv_flags, send_flags or socket_flags don't sound right.
> 
> If we tried to add networking stuff to io_uring (for batchinig and async), then:
>  - send()/recv() could work, only needs the "flags" field
>  - sendmsg()/recvmsg() likewise
>  - sendto()/recvfrom() require two more pointers: (struct sockaddr
> *dest_addr, socklen_t addrlen)
>  - sendmmsg() / recvmmsg() are perhaps irrelevant
> 
> Non-blocking stuff like socket(), setsockopt(), bind() perhaps don't
> need to be considered, although could benefit from batching.

If we just do separate opcodes for them, then there's 32 bits of flag
space for each one. That should be more than adequate.

> Not sure what to think about connect() and accept(). In the
> prehistoric days there seem to have been an attempt to add socket
> things to libaio struct iocb. See:
> 
> https://code.woboq.org/linux/include/libaio.h.html#iocb::(anonymous)::saddr
> 
> struct iocb {
>     ...
>     union {
>         ...
>         struct io_iocb_sockaddr    saddr;
>     } u;
> };
> 
> Are there chances of reserving space for two pointers in io_uring_sqe,
> which could be used for sendto/recvfrom/accept if we decided to add
> more network support?

There is already space for that. We have 3 x 64 bits at the end of the
sqe, 16 of those are used for the fixed buffers which networking
probably wants to support as well. But that still leaves 112 bits of
space for things opcode specific data.

-- 
Jens Axboe


      reply	other threads:[~2019-02-22 22:33 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-11 19:00 [PATCHSET v15] io_uring IO interface Jens Axboe
2019-02-11 19:00 ` [PATCH 01/19] fs: add an iopoll method to struct file_operations Jens Axboe
2019-02-11 19:00 ` [PATCH] io_uring: add io_uring_event cache hit information Jens Axboe
2019-02-11 19:00 ` [PATCH 02/19] block: wire up block device iopoll method Jens Axboe
2019-02-11 19:00 ` [PATCH 03/19] block: add bio_set_polled() helper Jens Axboe
2019-02-11 19:00 ` [PATCH 04/19] iomap: wire up the iopoll method Jens Axboe
2019-02-11 19:00 ` [PATCH 05/19] Add io_uring IO interface Jens Axboe
2019-02-11 19:00 ` [PATCH 06/19] io_uring: add fsync support Jens Axboe
2019-02-11 19:00 ` [PATCH 07/19] io_uring: support for IO polling Jens Axboe
2019-02-11 19:00 ` [PATCH 08/19] fs: add fget_many() and fput_many() Jens Axboe
2019-02-11 19:00 ` [PATCH 09/19] io_uring: use fget/fput_many() for file references Jens Axboe
2019-02-11 19:00 ` [PATCH 10/19] io_uring: batch io_kiocb allocation Jens Axboe
2019-02-11 19:00 ` [PATCH 11/19] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2019-02-20 22:58   ` Ming Lei
2019-02-21 17:45     ` Jens Axboe
2019-02-26  3:46       ` Eric Biggers
2019-02-26  4:34         ` Jens Axboe
2019-02-26 15:54           ` Jens Axboe
2019-02-27  1:21             ` Ming Lei
2019-02-27  1:47               ` Jens Axboe
2019-02-27  1:53                 ` Ming Lei
2019-02-27  1:57                   ` Jens Axboe
2019-02-27  2:21                     ` Ming Lei
2019-02-27  2:28                       ` Jens Axboe
2019-02-27  2:37                         ` Ming Lei
2019-02-27  2:43                           ` Jens Axboe
2019-02-27  3:09                             ` Ming Lei
2019-02-27  3:37                               ` Jens Axboe
2019-02-27  3:43                                 ` Jens Axboe
2019-02-27  3:44                                 ` Ming Lei
2019-02-27  4:05                                   ` Jens Axboe
2019-02-27  4:06                                     ` Jens Axboe
2019-02-27 19:42                                       ` Christoph Hellwig
2019-02-28  8:37                                         ` Ming Lei
2019-02-27 23:35                         ` Ming Lei
2019-03-08  7:55                         ` Christoph Hellwig
2019-03-08  9:12                           ` Ming Lei
2019-03-08  8:18                     ` Christoph Hellwig
2019-02-11 19:00 ` [PATCH 12/19] io_uring: add support for pre-mapped user IO buffers Jens Axboe
2019-02-19 19:08   ` Jann Horn
2019-02-22 22:29     ` Jens Axboe
2019-02-11 19:00 ` [PATCH 13/19] net: split out functions related to registering inflight socket files Jens Axboe
2019-02-11 19:00 ` [PATCH 14/19] io_uring: add file set registration Jens Axboe
2019-02-19 16:12   ` Jann Horn
2019-02-22 22:29     ` Jens Axboe
2019-02-11 19:00 ` [PATCH 15/19] io_uring: add submission polling Jens Axboe
2019-02-11 19:00 ` [PATCH 16/19] io_uring: add io_kiocb ref count Jens Axboe
2019-02-11 19:00 ` [PATCH 17/19] io_uring: add support for IORING_OP_POLL Jens Axboe
2019-02-11 19:00 ` [PATCH 18/19] io_uring: allow workqueue item to handle multiple buffered requests Jens Axboe
2019-02-11 19:00 ` [PATCH 19/19] io_uring: add io_uring_event cache hit information Jens Axboe
2019-02-21 12:10 ` [PATCHSET v15] io_uring IO interface Marek Majkowski
2019-02-21 17:48   ` Jens Axboe
2019-02-22 15:01     ` Marek Majkowski
2019-02-22 22:32       ` Jens Axboe [this message]

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=a75ebf28-66c0-4eaf-9c76-03843ce622b6@kernel.dk \
    --to=axboe@kernel.dk \
    --cc=avi@scylladb.com \
    --cc=hch@lst.de \
    --cc=jannh@google.com \
    --cc=jmoyer@redhat.com \
    --cc=linux-aio@kvack.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-block@vger.kernel.org \
    --cc=marek@cloudflare.com \
    --cc=viro@zeniv.linux.org.uk \
    /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).