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 4772DC433F5 for ; Fri, 1 Apr 2022 03:05:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244350AbiDADHF (ORCPT ); Thu, 31 Mar 2022 23:07:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234555AbiDADHE (ORCPT ); Thu, 31 Mar 2022 23:07:04 -0400 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9D6E193B6A for ; Thu, 31 Mar 2022 20:05:15 -0700 (PDT) Received: by mail-pf1-x42a.google.com with SMTP id y10so1385027pfa.7 for ; Thu, 31 Mar 2022 20:05:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language :from:to:cc:references:in-reply-to:content-transfer-encoding; bh=r7khBnonEiFThq13FqiG7LKVSQ+MeKxonEXk60vTiZk=; b=TAg1e9zBJTGmVQlIFL6G6CAqhYDbb5339K7GUDokxjlYMqdwqoz8hphzJUz6vFyzZp cBgh7/mOFVp2zT5x90Jr3DZ8JCaY90NURmqmn0Hzl1k9C934soglkbvMvJufqGHACvFs JYLLrnAunOVL6MNaKUdtNyh9xbWUVIELUeL62O3Si8bzhS05OWGwUiFQQAvOSI6QtNHx cFq/PJrXJzZTa0cwKj5Lx9JM8qfUAOG8uyPzjf/H9eeICIbDnWy8aBvV+OLCxX0cjt/t 9qH4BGFylh1FGR1l6hX8FIAxJ6i7wfgWG9jalSIiOTKsA+Z5BV0bW4qOUtPSA7Y3m57t FJsA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:from:to:cc:references:in-reply-to :content-transfer-encoding; bh=r7khBnonEiFThq13FqiG7LKVSQ+MeKxonEXk60vTiZk=; b=FC9h/OhVrKA06TDeZXsOhLle2koLA+8r1fVz8hYis+m0CzClFxcl4EIHC7oOfP9A1w LwjrlES5ut/EKUJPBcmefy2hrgH4vjyhvjtOk3qpmtcBJoUJliBICM0SXgK6r4eM7cuF lObcIU8d2BRx+bzCcnEJ5UTjKYnpnQ7r9M/w7GnbJnI1TmcEvUbcIDGsroF6AN3Poe93 CWBhXicLTxM++/wHHfUKgOqeehrobrPdAPS5srpaDA32F8EKdUqOuJjhnoKUtaiUGU9C TqsIpyyaSOkksNu3OaZ0O44lqp/YeH4Whtbjhk3MXskxiuKLIbHp+LuPUrZhAJu6O15c KNyw== X-Gm-Message-State: AOAM531nu39Yggd/oRAgvBgSjoQuuwPSahj8lfnnCiHwi84dJukzBVbM hZg3vmZOdkQuGvTzXciQjoyWCQ== X-Google-Smtp-Source: ABdhPJwf62CCz6zDtBAJs+C2QiuuIuYi30RJGbEXPrLs61j0DQUYOxVD0TojYqnwKOjPNvTYR/PrGQ== X-Received: by 2002:a05:6a00:ad0:b0:4e1:2d96:2ab0 with SMTP id c16-20020a056a000ad000b004e12d962ab0mr8542870pfl.3.1648782315250; Thu, 31 Mar 2022 20:05:15 -0700 (PDT) Received: from [192.168.1.100] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id ds15-20020a17090b08cf00b001c6a4974b45sm11003304pjb.40.2022.03.31.20.05.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 31 Mar 2022 20:05:14 -0700 (PDT) Message-ID: Date: Thu, 31 Mar 2022 21:05:12 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH 17/17] nvme: enable non-inline passthru commands Content-Language: en-US From: Jens Axboe To: Kanchan Joshi Cc: Christoph Hellwig , Kanchan Joshi , Keith Busch , Pavel Begunkov , io-uring@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, sbates@raithlin.com, logang@deltatee.com, Pankaj Raghav , =?UTF-8?Q?Javier_Gonz=c3=a1lez?= , Luis Chamberlain , Adam Manzanares , Anuj Gupta References: <20220308152105.309618-18-joshi.k@samsung.com> <20220310083652.GF26614@lst.de> <20220310141945.GA890@lst.de> <20220311062710.GA17232@lst.de> <20220324063218.GC12660@lst.de> <20220325133921.GA13818@test-zns> <20220330130219.GB1938@lst.de> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 3/31/22 8:44 PM, Jens Axboe wrote: > On 3/31/22 8:33 PM, Kanchan Joshi wrote: >> On Fri, Apr 1, 2022 at 6:55 AM Jens Axboe wrote: >>> >>> On 3/30/22 7:14 AM, Kanchan Joshi wrote: >>>> On Wed, Mar 30, 2022 at 6:32 PM Christoph Hellwig wrote: >>>>> >>>>> On Fri, Mar 25, 2022 at 07:09:21PM +0530, Kanchan Joshi wrote: >>>>>> Ok. If you are open to take new opcode/struct route, that is all we >>>>>> require to pair with big-sqe and have this sorted. How about this - >>>>> >>>>> I would much, much, much prefer to support a bigger CQE. Having >>>>> a pointer in there just creates a fair amount of overhead and >>>>> really does not fit into the model nvme and io_uring use. >>>> >>>> Sure, will post the code with bigger-cqe first. >>> >>> I can add the support, should be pretty trivial. And do the liburing >>> side as well, so we have a sane base. >> >> I will post the big-cqe based work today. It works with fio. >> It does not deal with liburing (which seems tricky), but hopefully it >> can help us move forward anyway . > > Let's compare then, since I just did the support too :-) > > Some limitations in what I pushed: > > 1) Doesn't support the inline completion path. Undecided if this is > super important or not, the priority here for me was to not pollute the > general completion path. > > 2) Doesn't support overflow. That can certainly be done, only > complication here is that we need 2x64bit in the io_kiocb for that. > Perhaps something can get reused for that, not impossible. But figured > it wasn't important enough for a first run. > > I also did the liburing support, but haven't pushed it yet. That's > another case where some care has to be taken to avoid makig the general > path slower. > > Oh, it's here, usual branch: > > https://git.kernel.dk/cgit/linux-block/log/?h=io_uring-big-sqe > > and based on top of the pending 5.18 bits and the current 5.19 bits. Do post your version too, would be interesting to compare. I just wired mine up to NOP, hasn't seen any testing beyond just verifying that we do pass back the extra data. Added inline completion as well. Kind of interesting in that performance actually seems to be _better_ with CQE32 for my initial testing, just using NOP. More testing surely needed, will run it on actual hardware too as I have a good idea what performance should look like there. I also think it's currently broken for request deferral and timeouts, but those are just minor tweaks that need to be made to account for the cq head being doubly incremented on bigger CQEs. -- Jens Axboe