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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7062FC76195 for ; Tue, 28 Mar 2023 01:29:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231990AbjC1B3l (ORCPT ); Mon, 27 Mar 2023 21:29:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232019AbjC1B3k (ORCPT ); Mon, 27 Mar 2023 21:29:40 -0400 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0DA051BC0 for ; Mon, 27 Mar 2023 18:29:39 -0700 (PDT) Received: by mail-pl1-x634.google.com with SMTP id iw3so10184553plb.6 for ; Mon, 27 Mar 2023 18:29:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; t=1679966978; x=1682558978; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=1Jdx37rOwHmakcXY70yxAvz0QRyJnQXhL1Wo5n+Z6Sk=; b=TLE59pC+XhSBCygxb2SEQVsD7yIPsQut3uSvtlKEheWJ2tzkUgAlKH9frRhvIaUuqf u5axdpbePlvEb5ATpAWhaGdNXbos48R6uC7ZbAzSfW8ih3A8GEldU1f1eowIC4Ws8IMo EPbbQFIlfrfrtOFpOQhheik/jRGwLZ9rpklmVa0fphD2Z9HZhm5FdEuXVVGsLqdAmDtY SIGWFw98Cu4PMyLREaSt7A8S1wFXdxRq9Nl8PtYX/CRUniY72xdzXRyIqL3NBFX2YE05 X7Fr31TeC9wsGIOz8kcnXi2Dmz2K7Y7mMR+xfLM1Dsg5LC9t1R19fhB2CqXrWUzQFQ9i kTSw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679966978; x=1682558978; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=1Jdx37rOwHmakcXY70yxAvz0QRyJnQXhL1Wo5n+Z6Sk=; b=oPaFETPy3gMbz4wV0RuaCWJqg1PZqrlSwxKxu5yvpf9Q4nM68iIVfpS++882U05K53 qq4tCxRf1GSeJnBQ7jNBfPudn7q241axdFZ0aPKnUqb3a5K8UowiGGpB7Bwp3F8Y031H iMIcifYxqc5wQ0YYeGk0Wg6bvpaeMPQW9Hvz2ormpgtLC/AxtylIXXvtu5MmDD7Wk7Uo FBuyNpsnL+misGh7WCQ8goMqrePi+MzqwM4eI42y/1b1UZKXkTL4R1ZogeOWW4zango/ 0/DPdB0cV0yFahPHc/Xl2QUdjl/DDPeD7vY7ZOP2nb0Bdz4OdVSvYDD0ToSKR1Bt64Gl XVBw== X-Gm-Message-State: AAQBX9dUXtK7D4U+8Y5AzSWtxoC0D+qBmWZK26vTpjnvvooJJRgVrwtr 5a1ub7NESagZvvgDvgIxyfmfBg== X-Google-Smtp-Source: AKy350YIXADcYKeGIQ+BYmeFKH3PssLjNKUaV/pDjDUzERdme6BuU5QYKfJDUlR2HCie59O54ufOqw== X-Received: by 2002:a17:903:788:b0:1a1:bf37:7c2e with SMTP id kn8-20020a170903078800b001a1bf377c2emr11609653plb.4.1679966978475; Mon, 27 Mar 2023 18:29:38 -0700 (PDT) Received: from [192.168.1.136] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id h20-20020a170902f7d400b001a0763fa8d6sm19820117plw.98.2023.03.27.18.29.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 27 Mar 2023 18:29:38 -0700 (PDT) Message-ID: <11651593-79d3-b21a-6441-63e1de5b39aa@kernel.dk> Date: Mon, 27 Mar 2023 19:29:36 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH V4 00/17] io_uring/ublk: add IORING_OP_FUSED_CMD Content-Language: en-US To: Ming Lei , Dan Williams Cc: io-uring@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Miklos Szeredi , ZiyangZhang , Xiaoguang Wang , Bernd Schubert , Pavel Begunkov , Stefan Hajnoczi References: <20230324135808.855245-1-ming.lei@redhat.com> <642236912a229_29cc2942c@dwillia2-xfh.jf.intel.com.notmuch> From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 3/27/23 7:16 PM, Ming Lei wrote: > Hi Dan, > > On Mon, Mar 27, 2023 at 05:36:33PM -0700, Dan Williams wrote: >> Ming Lei wrote: >>> Hello Jens, >>> >>> Add IORING_OP_FUSED_CMD, it is one special URING_CMD, which has to >>> be SQE128. The 1st SQE(master) is one 64byte URING_CMD, and the 2nd >>> 64byte SQE(slave) is another normal 64byte OP. For any OP which needs >>> to support slave OP, io_issue_defs[op].fused_slave needs to be set as 1, >>> and its ->issue() can retrieve/import buffer from master request's >>> fused_cmd_kbuf. The slave OP is actually submitted from kernel, part of >>> this idea is from Xiaoguang's ublk ebpf patchset, but this patchset >>> submits slave OP just like normal OP issued from userspace, that said, >>> SQE order is kept, and batching handling is done too. >> >> Hi Ming, >> >> io_uring and ublk are starting to be more on my radar these days. I >> wanted to take a look at this series, but could not get past the >> distracting "master"/"slave" terminology in this lead-in paragraph let >> alone start looking at patches. >> >> Frankly, the description sounds more like "head"/"tail", or even >> "fuse0"/"fuse1" because, for example, who is to say you might not have > > The term "master/slave" is from patches. > > The master command not only provides buffer for slave request, but also requires > slave request for serving master command, and master command is always completed > after all slave request are done. > > That is why it is named as master/slave. Actually Jens raised the similar concern > and I hate the name too, but it is always hard to figure out perfect name, or > any other name for reflecting the relation? (head/tail, fuse0/1 can't > do that, IMO) Indeed. What about primary/secondary? And it'd be quite possible to have multiple secondaries too. -- Jens Axboe