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 AABA0C761A6 for ; Tue, 28 Mar 2023 03:14:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229718AbjC1DOA (ORCPT ); Mon, 27 Mar 2023 23:14:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229497AbjC1DOA (ORCPT ); Mon, 27 Mar 2023 23:14:00 -0400 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2078D1A6; Mon, 27 Mar 2023 20:13:57 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R911e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0VerH6ke_1679973233; Received: from 30.221.134.40(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0VerH6ke_1679973233) by smtp.aliyun-inc.com; Tue, 28 Mar 2023 11:13:55 +0800 Message-ID: Date: Tue, 28 Mar 2023 11:13:53 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH V4 00/17] io_uring/ublk: add IORING_OP_FUSED_CMD To: Ming Lei , Dan Williams Cc: Jens Axboe , 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: Gao Xiang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 2023/3/28 09:16, 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) > >> larger fused ops in the future and need terminology to address >> "fuse{0,1,2,3}"? > > Yeah, definitely, the interface can be extended in future to support > multiple "slave" requests. I guess master/slave (especially now) have bad meaning to English-language guys so it's better to avoid it. Thanks, Gao Xiang > > Thanks, > Ming