From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 29A5AC33CA2 for ; Thu, 9 Jan 2020 14:59:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E95192072E for ; Thu, 9 Jan 2020 14:59:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=icloud.com header.i=@icloud.com header.b="Dg2xMIXF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732061AbgAIO6Q (ORCPT ); Thu, 9 Jan 2020 09:58:16 -0500 Received: from mr85p00im-ztdg06021701.me.com ([17.58.23.196]:39447 "EHLO mr85p00im-ztdg06021701.me.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732055AbgAIO6Q (ORCPT ); Thu, 9 Jan 2020 09:58:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=icloud.com; s=1a1hai; t=1578581895; bh=hHWKTZmVz6E9tqpH+pP3j2ANssvQuXEcmg9EhsFIAls=; h=From:Content-Type:Subject:Message-Id:Date:To; b=Dg2xMIXFDpDTwzeJrMmRxRYdvvoXG99Wz5ujqe6Ix6Me6Us3ZcvqGBP5V2umbT+/0 H3VfSTOVsav0Jo8dc1FVErv8hD10PWNm2wJTdbn/hEJBcgiqLLMNd6N6k/AgMAjwxY wdN+MHYNSMDkxVDAMMFpgdR6UMtAReUZ7KBTsqjVKD8ngc1Xo0a+BgpUd+HlVF3VZt 9zW9FhisoZk+8/o3gMc7rcO7dAVQOMXFebR7qSCTiwwXqJA5klem0uckPpHn9s+XcK 44dIRSNnXuii+bncW4iFjeBJu1fpU4iicTZYnhbmgXa/ZBalsOyyLTNNZwrtkz2am0 2VBgQuxs8YNnw== Received: from dhcp.her (louloudi.phaistosnetworks.gr [139.91.200.222]) by mr85p00im-ztdg06021701.me.com (Postfix) with ESMTPSA id 2E785A0127B for ; Thu, 9 Jan 2020 14:58:14 +0000 (UTC) From: Mark Papadakis Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 13.0 \(3608.40.2.2.4\)) Subject: Feature: zero-copy splice API/opcode Message-Id: Date: Thu, 9 Jan 2020 16:58:12 +0200 To: io-uring@vger.kernel.org X-Mailer: Apple Mail (2.3608.40.2.2.4) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2020-01-09_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 mlxscore=0 mlxlogscore=461 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-2001090131 Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Greetings, I =E2=80=98ve 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=E2=80=99t appear to work. Other = ideas didn=E2=80=99t 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. (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