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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74B42C433F5 for ; Tue, 12 Oct 2021 15:09:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 540E560527 for ; Tue, 12 Oct 2021 15:09:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234857AbhJLPL1 (ORCPT ); Tue, 12 Oct 2021 11:11:27 -0400 Received: from mail-wr1-f53.google.com ([209.85.221.53]:42943 "EHLO mail-wr1-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229565AbhJLPLZ (ORCPT ); Tue, 12 Oct 2021 11:11:25 -0400 Received: by mail-wr1-f53.google.com with SMTP id v17so67854449wrv.9; Tue, 12 Oct 2021 08:09:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=J1LZaElNrkRTt0L3TOQg6vlE4jRHoB3hzqVL1wIyGtw=; b=mKgt6g/gNF+O52SAApJuDICNAXPdQPiC7akJ2lapADCV6JfnbZ7eRuvIvHIYNaa5Xa eZECqFXEyNu7onbdtqor8iMbjNMvTtcT7mJ2gQDWNkXaG07cTG2YXoNKuIFIEzOxjhSK y8NRX4OQ6jPEZ3UWzxey4185m6TQxPHkzWxsGT8ddJQKUb7x3mEuRwNX5OG98jsotKqj ghThyWB5V2xe7yZJqCjcGU0bz+SI2VKbOOvD8YSwMC6Nq4CkssIRoyxADIeZDRl+uv40 3p0FXYI1vFHhb728QXSjWBKVPnNGFxYMf88JpU2jM/S+8XNb3ZE+MC7OfD+7yP90/3DK piAw== X-Gm-Message-State: AOAM532Vv2cbZkNHT1NA035IdX5Q5XR0VhXKd4v0Xd/KcMk+SkVJ9JWS LsQ3C3UYugxU/wK/D5dtncXo/vR3k7s= X-Google-Smtp-Source: ABdhPJzUa0NDblM2T2QL1+RHFgBKRczuoTxZUdRpZb6VVmvwDGzRabZJtooobPPXFM3WMF7ximyaQw== X-Received: by 2002:adf:a550:: with SMTP id j16mr33357712wrb.180.1634051362822; Tue, 12 Oct 2021 08:09:22 -0700 (PDT) Received: from [192.168.81.70] (bzq-219-42-90.isdn.bezeqint.net. [62.219.42.90]) by smtp.gmail.com with ESMTPSA id a63sm899421wmd.34.2021.10.12.08.09.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 12 Oct 2021 08:09:22 -0700 (PDT) Subject: Re: switch block layer polling to a bio based model v4 To: Jens Axboe , Christoph Hellwig Cc: Jeffle Xu , Ming Lei , Damien Le Moal , Keith Busch , "Vasudevan, Anil" , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nvme@lists.infradead.org References: <20211012111226.760968-1-hch@lst.de> <07f31547-5570-4150-7a4b-1d773fb9fa87@kernel.dk> <040104f6-720d-35ed-7e15-a704e6488fd4@grimberg.me> <1f53ea37-6825-de63-0f51-5ff54fa7618e@kernel.dk> From: Sagi Grimberg Message-ID: <054cd2ed-1996-d6dd-5842-2bf5a03fbdea@grimberg.me> Date: Tue, 12 Oct 2021 18:09:20 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <1f53ea37-6825-de63-0f51-5ff54fa7618e@kernel.dk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 10/12/21 5:58 PM, Jens Axboe wrote: > On 10/12/21 8:57 AM, Sagi Grimberg wrote: >> >>>> Hi all, >>>> >>>> This series clean up the block polling code a bit and changes the interface >>>> to poll for a specific bio instead of a request_queue and cookie pair. >>>> >>>> Polling for the bio itself leads to a few advantages: >>>> >>>> - the cookie construction can made entirely private in blk-mq.c >>>> - the caller does not need to remember the request_queue and cookie >>>> separately and thus sidesteps their lifetime issues >>>> - keeping the device and the cookie inside the bio allows to trivially >>>> support polling BIOs remapping by stacking drivers >>>> - a lot of code to propagate the cookie back up the submission path can >>>> removed entirely >>>> >>>> The one major caveat is that this requires RCU freeing polled BIOs to make >>>> sure the bio that contains the polling information is still alive when >>>> io_uring tries to poll it through the iocb. For synchronous polling all the >>>> callers have a bio reference anyway, so this is not an issue. >>> >>> I ran this through the usual peak testing, and it doesn't seem to regress >>> anything for me. We're still at around ~7.4M polled IOPS on a single CPU >>> core: >>> >>> taskset -c 0,16 t/io_uring -d128 -b512 -s32 -c32 -p1 -F1 -B1 -D1 -n2 /dev/nvme1n1 /dev/nvme2n1 >>> Added file /dev/nvme1n1 (submitter 0) >>> Added file /dev/nvme2n1 (submitter 1) >>> polled=1, fixedbufs=1, register_files=1, buffered=0, QD=128 >>> Engine=io_uring, sq_ring=128, cq_ring=256 >>> submitter=0, tid=1199 >>> submitter=1, tid=1200 >>> IOPS=7322112, BW=3575MiB/s, IOS/call=32/31, inflight=(110 71) >>> IOPS=7452736, BW=3639MiB/s, IOS/call=32/31, inflight=(52 80) >>> IOPS=7419904, BW=3623MiB/s, IOS/call=32/31, inflight=(78 104) >>> IOPS=7392576, BW=3609MiB/s, IOS/call=32/32, inflight=(75 102) >> >> Jens, is that with nvme_core.multipath=Y ? > > No, I don't have multipath enabled. I can run that too, if you'd like. That would be useful to learn. thanks. 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5784C433F5 for ; Tue, 12 Oct 2021 15:09:38 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9684F6052B for ; Tue, 12 Oct 2021 15:09:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9684F6052B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=grimberg.me Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:Cc:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=sD46WWgzAObSAcghdvkIp8oMObNkXZIkiaixyiqmeBs=; b=1A/4PorO/J7QJfkZthl5x55Xdk Pn0OZiB9NlYYCJfLXWXMhL92FRYWCqY2ooJRp8hx1GSYGQ8WaD0fmowPDfsmZLq7sbGcVLC2VZaEb tCxsYOPQTHkckrryQbv9NnSDyZ3ue1v0yj1zQcKrGOZ75XrccJhfWN+4xyaVgbKKI9kTFG0wLTAJW MsGJweRX2vszCJIuy4CIB/bogh1aD0TF0ZI0B4jUdQcsrozz9tI65fiSvkrYyFcpF/adaboVbtVJJ boLyWrAGokmIlyB5Cts996UZ2oyYYRowMANNGaC70qsOv3lERt3+/WWrlwgj5kziP9+AemsKDfs2V Kcxj8mhg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1maJPE-00DIkS-Bd; Tue, 12 Oct 2021 15:09:28 +0000 Received: from mail-wr1-f52.google.com ([209.85.221.52]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1maJPB-00DIjW-7k for linux-nvme@lists.infradead.org; Tue, 12 Oct 2021 15:09:26 +0000 Received: by mail-wr1-f52.google.com with SMTP id t2so67953017wrb.8 for ; Tue, 12 Oct 2021 08:09:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=J1LZaElNrkRTt0L3TOQg6vlE4jRHoB3hzqVL1wIyGtw=; b=zcqQ1/rgeGstosNwPvpl1TKErdP8nJmd9cX6W0A+76tL+NqoVYN3JVDW8yETuS9QcN +QOD6s/nwxyBnEZgp0ro4kCotWPHAkP2s5Ia/y839OMqV+x+PEkNqRASbjNhLgrKUJ3D bIvH6A9Lubt77udg04dsJkhHPrjNAxFpGLYTMRWGVSuo3ypl9T1refbdKJF6iN8Ae03P J11hLtxDKSD3fRsrwFQNzNElAn+sy0dvgN+KCst9jLoGc02bkISx2/A1c/+A8oQjT2jj QizitDL9G+/WYTlR9Ql5UunjosYB968Ubpz0QM6zFmEutpR7dTT8lA9kfx0xKie8Vrh0 k8YQ== X-Gm-Message-State: AOAM5335HSszpzhH8BteJ9TJXQ5cjJypc7MR97L7RrRw6qAyP1c4ljHS 5obvNfN6kwz3QDiuNM/jnHqQTqEgSWI= X-Google-Smtp-Source: ABdhPJzUa0NDblM2T2QL1+RHFgBKRczuoTxZUdRpZb6VVmvwDGzRabZJtooobPPXFM3WMF7ximyaQw== X-Received: by 2002:adf:a550:: with SMTP id j16mr33357712wrb.180.1634051362822; Tue, 12 Oct 2021 08:09:22 -0700 (PDT) Received: from [192.168.81.70] (bzq-219-42-90.isdn.bezeqint.net. [62.219.42.90]) by smtp.gmail.com with ESMTPSA id a63sm899421wmd.34.2021.10.12.08.09.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 12 Oct 2021 08:09:22 -0700 (PDT) Subject: Re: switch block layer polling to a bio based model v4 To: Jens Axboe , Christoph Hellwig Cc: Jeffle Xu , Ming Lei , Damien Le Moal , Keith Busch , "Vasudevan, Anil" , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nvme@lists.infradead.org References: <20211012111226.760968-1-hch@lst.de> <07f31547-5570-4150-7a4b-1d773fb9fa87@kernel.dk> <040104f6-720d-35ed-7e15-a704e6488fd4@grimberg.me> <1f53ea37-6825-de63-0f51-5ff54fa7618e@kernel.dk> From: Sagi Grimberg Message-ID: <054cd2ed-1996-d6dd-5842-2bf5a03fbdea@grimberg.me> Date: Tue, 12 Oct 2021 18:09:20 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <1f53ea37-6825-de63-0f51-5ff54fa7618e@kernel.dk> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211012_080925_312274_291199F1 X-CRM114-Status: GOOD ( 21.07 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 10/12/21 5:58 PM, Jens Axboe wrote: > On 10/12/21 8:57 AM, Sagi Grimberg wrote: >> >>>> Hi all, >>>> >>>> This series clean up the block polling code a bit and changes the interface >>>> to poll for a specific bio instead of a request_queue and cookie pair. >>>> >>>> Polling for the bio itself leads to a few advantages: >>>> >>>> - the cookie construction can made entirely private in blk-mq.c >>>> - the caller does not need to remember the request_queue and cookie >>>> separately and thus sidesteps their lifetime issues >>>> - keeping the device and the cookie inside the bio allows to trivially >>>> support polling BIOs remapping by stacking drivers >>>> - a lot of code to propagate the cookie back up the submission path can >>>> removed entirely >>>> >>>> The one major caveat is that this requires RCU freeing polled BIOs to make >>>> sure the bio that contains the polling information is still alive when >>>> io_uring tries to poll it through the iocb. For synchronous polling all the >>>> callers have a bio reference anyway, so this is not an issue. >>> >>> I ran this through the usual peak testing, and it doesn't seem to regress >>> anything for me. We're still at around ~7.4M polled IOPS on a single CPU >>> core: >>> >>> taskset -c 0,16 t/io_uring -d128 -b512 -s32 -c32 -p1 -F1 -B1 -D1 -n2 /dev/nvme1n1 /dev/nvme2n1 >>> Added file /dev/nvme1n1 (submitter 0) >>> Added file /dev/nvme2n1 (submitter 1) >>> polled=1, fixedbufs=1, register_files=1, buffered=0, QD=128 >>> Engine=io_uring, sq_ring=128, cq_ring=256 >>> submitter=0, tid=1199 >>> submitter=1, tid=1200 >>> IOPS=7322112, BW=3575MiB/s, IOS/call=32/31, inflight=(110 71) >>> IOPS=7452736, BW=3639MiB/s, IOS/call=32/31, inflight=(52 80) >>> IOPS=7419904, BW=3623MiB/s, IOS/call=32/31, inflight=(78 104) >>> IOPS=7392576, BW=3609MiB/s, IOS/call=32/32, inflight=(75 102) >> >> Jens, is that with nvme_core.multipath=Y ? > > No, I don't have multipath enabled. I can run that too, if you'd like. That would be useful to learn. thanks. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme