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 472F7C433F5 for ; Tue, 12 Oct 2021 14:58:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20EBC6103D for ; Tue, 12 Oct 2021 14:58:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237358AbhJLPAu (ORCPT ); Tue, 12 Oct 2021 11:00:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237062AbhJLPAu (ORCPT ); Tue, 12 Oct 2021 11:00:50 -0400 Received: from mail-io1-xd2a.google.com (mail-io1-xd2a.google.com [IPv6:2607:f8b0:4864:20::d2a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E510C061570 for ; Tue, 12 Oct 2021 07:58:48 -0700 (PDT) Received: by mail-io1-xd2a.google.com with SMTP id r134so12837657iod.11 for ; Tue, 12 Oct 2021 07:58:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=tqA23ObcMjBgZVvCWLFVqQeiCNLoGDBftx5XWNNYGp8=; b=1Ysqi5Tuua6c+DOLSCokMMRS0S3ouQULZDGn4I6OUS6O8h961XDJX5twQE8MEv3sYV yLKA+6+hnbhAFFd4liTVO0RAFAkhGdM/S74YHZB8IDjSJy7RI7fhnHIXklQCCs8tle6N 4CC3iMtQeDwfxmML9nUnM23Mfe7YcrnJ1unghGz8N4xotNALRNSq4IKGWQxEJHDs6as0 +/OD/rLxQ3TOY/Hj8Y5TUiXurkChyAiiljPthkqsePedmYW0D8a3EOhBhu/zsdhi2vQK c4L7JJLs0hXqLKYLbj3GRqS19j9cqxaDQp6KDApM/GdqunKznW5jYFku3mRxppSz02G0 T3KA== 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=tqA23ObcMjBgZVvCWLFVqQeiCNLoGDBftx5XWNNYGp8=; b=Q+pc16/U6Z695EdWcy9FqVVuVTNmraUahoFsHpTeYET4nzm1nJtR1tzK4B2iU3A+A2 /X0h3bz5OhL12oU+ugy7F0BQYWJwEjVDiPR6KiqbWm2Q6cQ4e3lBswvXzxRTWtWKaqOr OXgcXTHSbQPQF7jXxv6gz2gcudiHSlkvWL++W4MS4cuRElls0fwEnBp8vJfUFp00/sBv 2ZA8BozGXoJnZjPvMznZkusw/90Kr9P7/8FRwMX0gjmOfvHIWYczzSJGTu+CG6aB/XQ1 XAURPm/fqTme89KkuzJSBQbsvodRB+4tBRnIUM3qwW4IZg25Cc2cDnbIp20qRawUVSFv 5uBA== X-Gm-Message-State: AOAM531V+KQES2cW8xHOVRtNFfBxpiBz4qaPVe23T3qviAsKyMU95O1u Ntg5K5Cc8STZr+aG1jqxS4YwgA== X-Google-Smtp-Source: ABdhPJyv1Javrn/St42VuUvMZqKad4SdoRQwzO4D5Q9r1lS2yVB+cCZF7l5V9bE9h582nw9V5kHLyg== X-Received: by 2002:a6b:8e52:: with SMTP id q79mr21218840iod.64.1634050727820; Tue, 12 Oct 2021 07:58:47 -0700 (PDT) Received: from [192.168.1.30] ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id c9sm5649857ilo.18.2021.10.12.07.58.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 12 Oct 2021 07:58:47 -0700 (PDT) Subject: Re: switch block layer polling to a bio based model v4 To: Sagi Grimberg , Christoph Hellwig Cc: Jeffle Xu , Ming Lei , Damien Le Moal , Keith Busch , "Wunderlich, Mark" , "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> From: Jens Axboe Message-ID: <1f53ea37-6825-de63-0f51-5ff54fa7618e@kernel.dk> Date: Tue, 12 Oct 2021 08:58:46 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <040104f6-720d-35ed-7e15-a704e6488fd4@grimberg.me> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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. -- Jens Axboe