From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751644AbdJEOOz (ORCPT ); Thu, 5 Oct 2017 10:14:55 -0400 Received: from mailout3.samsung.com ([203.254.224.33]:49295 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751319AbdJEOOv (ORCPT ); Thu, 5 Oct 2017 10:14:51 -0400 X-AuditID: b6c32a38-d89ff70000001124-56-59d63e58c089 From: Bartlomiej Zolnierkiewicz To: "Hunter, Adrian" Cc: Linus Walleij , Ulf Hansson , linux-mmc , linux-block , linux-kernel , Bough Chen , Alex Lemberg , "Nowak, Mateusz" , Yuliy Izrailov , Jaehoon Chung , Dong Aisheng , Das Asutosh , Zhangfei Gao , Sahitya Tummala , Harjani Ritesh , Venu Byravarasu , Shawn Lin , Christoph Hellwig Subject: Re: [PATCH V9 13/15] mmc: block: Add CQE and blk-mq support Date: Thu, 05 Oct 2017 16:14:45 +0200 Message-id: <1916712.dEBEVKDoTZ@amdc3058> User-Agent: KMail/4.13.3 (Linux/3.13.0-96-generic; KDE/4.13.3; x86_64; ; ) In-reply-to: <1591139.5Ihy91Pq6o@amdc3058> MIME-version: 1.0 Content-transfer-encoding: 7Bit Content-type: text/plain; charset="us-ascii" X-Brightmail-Tracker: H4sIAAAAAAAAA02Sa0hTYRjHe8/ZOdvMxWnTelMqmBW4yguovZRJhdEh/OCHIE0oZx7Uciqb iuaHzGyGeS1vTcEuhrm84AWdOifMy9Q0NW15x0LNZloiK7OknEfBb7/3+f+f5/m/Ly8PFw4R drywiGhGHiENF5NWnPo2R6eTfl5Gf5fxeT7qnikn0ej0KolalF1ctF6bT6LMD2UAlb3pwNDI mpJAOX9LMdQydhwNNRWRqP1fJkD3Vicx1LowQKCJmSoCDdatcJGh4ir6rM/GkT63i0RJpVPY ORE9lJGO0Y2qSS79UvsVoyeMWpJuHk0k6fT7SyRdvaTB6HVVK4fOqFMDOq+8H6NXag757r5m 5RnMhIfFMnJnr0Cr0LEiDYh6ax2X+WUeTwQj/FTA50HKDVaou3ALCykNgMnp7qnAaoN/AVhT koNvm9Td/YAVmgFsWB7fOpgBXG3vwiwukjoNs1PUwMI2lBNsVxZwLIxTswRsKXSwsIjyhnPm Eq6FOdRR2PmtlLSwgHKEi4+SNuu21GVYp0vZnMmnJNCQu8ZlPXvh6pOprZmHoa41l2D5BOzr rNwMBCkdF471DnPY2N5wOWNgi0XQZKjbGMTbYHv4vuMsW87fuM0fyPbWAqhuzuKywhnYZhjc WrAHLpnTCLZXAB8qhayFhqPfXxMsn4e/jW0E+yjJGKwtr8eywEHVjtyqHblVO3I/A7ga7GOi FLIQRuEa5eakkMoUMREhTjcjZTVg86tJkAZo3/noAcUDYmvBrulhfyEhjVXEy/QA8nCxjcDe 0+gvFARL4+8w8sgb8phwRqEH9jyOeL/AtsroJ6RCpNHMbYaJYuTbKsbj2yUCj8Lip5eSzBeq Go2P5340f9TNjrqBJmOlzNlx5YBJYpo2Ldq5TETebVkGibr5gp7AwrSAK72xGQ7BEh+mZPnn gvbYxeoAc1+ne5DJMSDniDKnWPq8xBdfeBH0wNAzPnvqU5wHdqtMNNMRO0BcH7YVOQsTQEJT 5iv7vAZJ/nqtmKMIlbpKcLlC+h91iF/8ZgMAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrDIsWRmVeSWpSXmKPExsVy+t9jAd1wu2uRBg+nyVmcfLKGzeLmgx9s FnvbTrBb/N08nc2i/+pKRouVq48yWdz41cZqMeXPciaLvbe0LS7vmsNmceR/P6NF44+7TBb7 X19gtbjzZD2rxcUtn9ktjq8Nt3h0aCKzxaGpJ9gsmpbfY3IQ9rjc18vksXPWXXaPxXteMnnc ubaHzWP3zQY2j97md2weG9/tYPL4O2s/i0ffllWMHtPWnGfy+LxJLoA7issmJTUnsyy1SN8u gSvj1pwdjAWneSr6n79gbmC8wdnFyMkhIWAiserkecYuRi4OIYGdjBLrLixignC+MkrMOLaJ CaSKTcBKYmL7KkYQW0RAT+JI2wwWEJtZ4CWrxLb7PiC2sICLxLOvS9hBbBYBVYljb5azgdi8 ApoSb7ubwOKiAl4SW/a1g83kFNCSOD71F1hcSGADo8SkR3oQ9YISPybfg5ovL7Fv/1RWCFtL Yv3O40wTGPlnISmbhaRsFpKyBYzMqxglUwuKc9Nzi40KDPNSy/WKE3OLS/PS9ZLzczcxAuNw 22Gtvh2M95fEH2IU4GBU4uGNeHQlUog1say4MvcQowQHs5IIr7TNtUgh3pTEyqrUovz4otKc 1OJDjNIcLErivLfzjkUKCaQnlqRmp6YWpBbBZJk4OKUaGNVkwo/rb5L2Muyebz61cWLEgZpN RR9797dP7A2q2f9D6PSSX7VKSV/a3ZKNjsnckXQ+ae4YO+dL3kMXLsuXczxuMUXvbFCfnJQp IXJ12cJfNtH5F9yNuKoOrU1KnLyN6dshxf4VnjNWJuyxUrtoWyHzfu6KMOMn14/rB858oxIY 239yc4fvLiWW4oxEQy3mouJEAH4JTM6/AgAA X-CMS-MailID: 20171005141447epcas1p42fc9f210c5c00824d19824ebb01906b6 X-Msg-Generator: CA X-Sender-IP: 182.195.42.142 X-Local-Sender: =?UTF-8?B?QmFydGxvbWllaiBab2xuaWVya2lld2ljehtTUlBPTC1LZXJu?= =?UTF-8?B?ZWwgKFRQKRvsgrzshLHsoITsnpAbU2VuaW9yIFNvZnR3YXJlIEVuZ2luZWVy?= X-Global-Sender: =?UTF-8?B?QmFydGxvbWllaiBab2xuaWVya2lld2ljehtTUlBPTC1LZXJu?= =?UTF-8?B?ZWwgKFRQKRtTYW1zdW5nIEVsZWN0cm9uaWNzG1NlbmlvciBTb2Z0d2FyZSBF?= =?UTF-8?B?bmdpbmVlcg==?= X-Sender-Code: =?UTF-8?B?QzEwG0VIURtDMTBDRDAyQ0QwMjczOTI=?= CMS-TYPE: 101P X-CMS-RootMailID: 20171005141447epcas1p42fc9f210c5c00824d19824ebb01906b6 X-RootMTR: 20171005141447epcas1p42fc9f210c5c00824d19824ebb01906b6 References: <1506083824-4024-1-git-send-email-adrian.hunter@intel.com> <363DA0ED52042842948283D2FC38E4649BF33EFD@IRSMSX106.ger.corp.intel.com> <1591139.5Ihy91Pq6o@amdc3058> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, October 05, 2017 02:00:48 PM Bartlomiej Zolnierkiewicz wrote: > > > > I am trying to wrap my head around this large patch. The size makes it > > > > hard but I am doing my best. > > > > > > I also think that this patch should be split on two patches. The 1st one > > > introducing blk-mq and the 2nd one adding CQE support. > > > > > > [ I don't agree that they make more sense together, on the contrary, > > > it is very difficult to properly analyze blk-mq changes on their > > > own while there are mixed with CQE related ones. ] > > > > The CQE and non-CQE code paths are clearly marked. But maybe you > > The combined patch is > 1 kLOC which is a lot and since the CQE and > non-CQE code paths are clearly marked it should be really easy to > split them. > > > are asking what the code would look like if we *never* had to support CQE. > > And my point is we *do* have to support CQE. > > We *do* but not in the same step, it is just normal kernel engineering > practice to split patches on logical changes. This is not asking about > something extraordinary. BTW: I sympathize with you that it takes long time to get CQE merged upstream and that you weren't told earlier that no new users of the old block API are welcomed. However since "mmc-mq" support has to be added as a preparation for CQE please try do it *properly* and also consider that many people may want just "mmc-mq" without CQE as their hardware simply doesn't support CQE. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics