Linux-Block Archive on lore.kernel.org
 help / color / Atom feed
From: Marek Majkowski <marek@cloudflare.com>
To: Jens Axboe <axboe@kernel.dk>
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 16:01:00 +0100
Message-ID: <CAJPywTLGBRviKYSf+AQg-0eOZ3pnyTFEhr28no9Zrh8ftsSxmQ@mail.gmail.com> (raw)
In-Reply-To: <e9b96cd8-71a1-d5bc-e3cf-8248f9654deb@kernel.dk>

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.

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?

Cheers,
    Marek

> If you're talking on a per-syscall type of flag, io_uring_enter(2)
> does take a flags member.
>
> --
> Jens Axboe
>

  reply index

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-11 19:00 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 [this message]
2019-02-22 22:32       ` Jens Axboe

Reply instructions:

You may reply publically 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=CAJPywTLGBRviKYSf+AQg-0eOZ3pnyTFEhr28no9Zrh8ftsSxmQ@mail.gmail.com \
    --to=marek@cloudflare.com \
    --cc=avi@scylladb.com \
    --cc=axboe@kernel.dk \
    --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=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

Linux-Block Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-block/0 linux-block/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-block linux-block/ https://lore.kernel.org/linux-block \
		linux-block@vger.kernel.org linux-block@archiver.kernel.org
	public-inbox-index linux-block

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-block


AGPL code for this site: git clone https://public-inbox.org/ public-inbox