IO-Uring Archive on lore.kernel.org
 help / color / Atom feed
From: Pavel Begunkov <asml.silence@gmail.com>
To: Mark Papadakis <markuspapadakis@icloud.com>, io-uring@vger.kernel.org
Subject: Re: Feature: zero-copy splice API/opcode
Date: Mon, 13 Jan 2020 00:21:04 +0300
Message-ID: <457632cf-614c-ac55-b869-39b50a61e1fd@gmail.com> (raw)
In-Reply-To: <CBBC10BD-9497-4248-9E6A-AF2DE788E401@icloud.com>

[-- Attachment #1.1: Type: text/plain, Size: 1151 bytes --]

On 09/01/2020 17:58, Mark Papadakis wrote:
> Greetings,
> 
> I ‘ve been trying to replicate the benefits provided by sendfile() using e.g O_DIRECT access, together with IOSQE_IO_LINK in SQE flags and MSG_ZEROCOPY, but it doesn’t appear to work. Other ideas didn’t work either.
> 
> I would really appreciate a sendfile like SQE opcode, but maybe some sort of generic DMA/zero-copy based opcode based on splice semantics could be implemented, so that e.g a vmsplice() like alternative could also work.
> 
Sounds interesting, I'll look into this. First, I want to dig a bit into
kernel's zero-copy and get an idea how to cover all use cases with a single
opcode, and that's probably keeping in mind p2p.

The obvious nuisance from  perspective is that it needs 2 fds. Any other concerns?

> 
> (That would be the last remaining bit of functionality missing from io_uring, now that Jens has implemented support for IOSQE_ASYNC, IORING_REGISTER_EVENTFD_ASYNC and for managing epoll FDs, for enabling support for io_uring on https://github.com/phaistos-networks/TANK ).
> 
> Thank you,
> @markpapadakis
> 

-- 
Pavel Begunkov


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

      reply index

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-09 14:58 Mark Papadakis
2020-01-12 21:21 ` Pavel Begunkov [this message]

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=457632cf-614c-ac55-b869-39b50a61e1fd@gmail.com \
    --to=asml.silence@gmail.com \
    --cc=io-uring@vger.kernel.org \
    --cc=markuspapadakis@icloud.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

IO-Uring Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/io-uring/0 io-uring/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 io-uring io-uring/ https://lore.kernel.org/io-uring \
		io-uring@vger.kernel.org
	public-inbox-index io-uring

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.io-uring


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