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 04575C433EF for ; Wed, 23 Mar 2022 01:41:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238535AbiCWBnJ (ORCPT ); Tue, 22 Mar 2022 21:43:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231799AbiCWBnI (ORCPT ); Tue, 22 Mar 2022 21:43:08 -0400 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38C876FF58 for ; Tue, 22 Mar 2022 18:41:40 -0700 (PDT) Received: by mail-pj1-x102a.google.com with SMTP id q1-20020a17090a4f8100b001c6575ae105so3045441pjh.0 for ; Tue, 22 Mar 2022 18:41:40 -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:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=8LWS8Tu499Dz/WYM5ibp7anTuYd4mn6MZuCdOuBE178=; b=u9tJ+j3d5YI5UgkOXDz2XUOElZhozk7XiIImUcObs2/Az2WbY+KAayscuv/jhpR0lW /KyzGwNTrBI+9G26XDRspZxZ+TYgY2VlkaNV9hh5bk4E4s4A+bey9jYPZnvPmDguhftd SuKuWOF5uGvH9HXJsoSLP1bN9Dr0+OtlzKpP9yx2iMvyT4xdSMG83IzkGgta9xeRqyt+ jxh67C/URFXKOoKfYkAGPc0UuPctb1Tg2tL61c6V4PqnEuRgMLxxDhQ3Igq+43QRLE3D pjpuYqK8hcDHFpPl5ixI+QERnYJLOcFJ0kl87pHI4awZx3wqN4f5uXY2g/tPwVOkSa46 Mm2A== 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:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=8LWS8Tu499Dz/WYM5ibp7anTuYd4mn6MZuCdOuBE178=; b=A4cmbTE8dCJIG9HyF9wTWXJ+tkF25SLWTZ73VVNb9MalkhNrw7XsCDR2m5VuP67wbf NKPkPOoyMuNISZZ7a315VLcKEe59cYQ1K7KXXGsogZJD5NqSw4hxJsS2OCdpVN6YNSod Uqr0sLv3LPsUHdD7N6mPfLqcZBTTGHCPMCMw6E3GCxG2UKVQm2JIWm3wrjZqhecigFd+ nv5KRVjDnB/MzRa5KR+TrrV2DN7Q6KIBnfLzJ2yKKfjzXTfAcWJ55uXMQWfawiPAvRE8 vB/68d9PRWDJ8ZEFhTAaFaXOcED/3mJz1sMCIISVrZg2X+QvaKFl4Mkj+/4Vcik6ObDw ouyg== X-Gm-Message-State: AOAM532aUF0KqnNISfwFOiLRtxEO+DEETb0tqoIhZb+xjgxTAJwSI+Q7 jMF3W1Abm5LSyBVhv5rCBbcitg== X-Google-Smtp-Source: ABdhPJxSRgW3m5jc7fEsNBHY6ceeLuGkLIYrOQuznfb7ISQCvU9m/1ZRig2qgrKGxL/KbKf6/RShzQ== X-Received: by 2002:a17:90a:d50a:b0:1c6:aade:e4b3 with SMTP id t10-20020a17090ad50a00b001c6aadee4b3mr8657340pju.69.1647999699606; Tue, 22 Mar 2022 18:41:39 -0700 (PDT) Received: from [192.168.1.100] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id w9-20020aa78589000000b004f78b5a4499sm22510061pfn.206.2022.03.22.18.41.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 22 Mar 2022 18:41:39 -0700 (PDT) Message-ID: Date: Tue, 22 Mar 2022 19:41:37 -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 10/17] block: wire-up support for plugging Content-Language: en-US To: Ming Lei , Kanchan Joshi Cc: Kanchan Joshi , Christoph Hellwig , 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: <20220308152105.309618-1-joshi.k@samsung.com> <20220308152105.309618-11-joshi.k@samsung.com> <20220310083400.GD26614@lst.de> <20220321070208.GA5107@test-zns> From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 3/22/22 7:27 PM, Ming Lei wrote: > On Mon, Mar 21, 2022 at 12:32:08PM +0530, Kanchan Joshi wrote: >> On Mon, Mar 14, 2022 at 10:40:53PM +0800, Ming Lei wrote: >>> On Thu, Mar 10, 2022 at 06:10:08PM +0530, Kanchan Joshi wrote: >>>> On Thu, Mar 10, 2022 at 2:04 PM Christoph Hellwig wrote: >>>>> >>>>> On Tue, Mar 08, 2022 at 08:50:58PM +0530, Kanchan Joshi wrote: >>>>>> From: Jens Axboe >>>>>> >>>>>> Add support to use plugging if it is enabled, else use default path. >>>>> >>>>> The subject and this comment don't really explain what is done, and >>>>> also don't mention at all why it is done. >>>> >>>> Missed out, will fix up. But plugging gave a very good hike to IOPS. >>> >>> But how does plugging improve IOPS here for passthrough request? Not >>> see plug->nr_ios is wired to data.nr_tags in blk_mq_alloc_request(), >>> which is called by nvme_submit_user_cmd(). >> >> Yes, one tag at a time for each request, but none of the request gets >> dispatched and instead added to the plug. And when io_uring ends the >> plug, the whole batch gets dispatched via ->queue_rqs (otherwise it used >> to be via ->queue_rq, one request at a time). >> >> Only .plug impact looks like this on passthru-randread: >> >> KIOPS(depth_batch) 1_1 8_2 64_16 128_32 >> Without plug 159 496 784 785 >> With plug 159 525 991 1044 >> >> Hope it does clarify. > > OK, thanks for your confirmation, then the improvement should be from > batch submission only. > > If cached request is enabled, I guess the number could be better. Yes, my original test patch pre-dates being able to set a submit count, it would definitely help improve this case too. The current win is indeed just from being able to use ->queue_rqs() rather than single submit. -- Jens Axboe