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 X-Spam-Level: X-Spam-Status: No, score=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72A1CC2BBCF for ; Tue, 15 Dec 2020 01:08:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4878E20731 for ; Tue, 15 Dec 2020 01:08:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727964AbgLOBHy (ORCPT ); Mon, 14 Dec 2020 20:07:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726662AbgLOBHr (ORCPT ); Mon, 14 Dec 2020 20:07:47 -0500 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6AD80C061793; Mon, 14 Dec 2020 17:07:07 -0800 (PST) Received: by mail-wr1-x443.google.com with SMTP id q18so10685544wrn.1; Mon, 14 Dec 2020 17:07:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:cc:references:from:autocrypt:subject:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=k+K/DZUEOzK/FQdjk7VqHxa5bhLpoT0KZ6XUenKr/m4=; b=nuP+UqiRHhLGz4gGtD2Vo5H7UxvUsullWHNiG0+Kgvw1dG6LKHf+qha3LGG6jOtBDI 4U9aD7comb9UXrFPzF6lAJX5elYArM3OsMiTFHc86CaRljL9RrCSWwIGghcXTwtvs5Gt gyOyoTMZypF/zeH2AOpJ/wxGyxTM9wxMpel3S34IEFkeG6zQOfg7RuLYtxZNs0jPaHJS bjveKb9dn7K4EBEVqDqod0Ov6mVUQIwYZ4/0s1kwImyfEHya+SKmsYXobZzta/SJgB7c Dl1kHsLdcsvCznY9YSt8GnEUJDCm6mv6r3o7TYkcAf+Wep55ktjJ/QZG181UDIS8vWdk PwJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:references:from:autocrypt:subject :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=k+K/DZUEOzK/FQdjk7VqHxa5bhLpoT0KZ6XUenKr/m4=; b=r2CCORBu6HjmQ6yJUT/3DLo0jQ/rVTzXcGGylfUJHj4KaXnZpEGb+M5J+NMq1RI6t3 hB1HrDHu/zX9rj5oPL9YsYxDWNPPd1m3WuXCT8J19GVOQsJy66+7F1r3lwjz80EszVZt Xe2DN2WBI58hPua2OcvEKbwTCche2zd9ZncNmDDUQ0uMjAaXNy8A+ypdI0bfqaE3nIIQ I07vOgWdL+i6v+o/iknYJoU5YslBZnoWXXiRE8ZrmlqoQVoQfCwjJYgUOQC9vBpmTLUV NEVs49RmeLypTlTqefHirgr6ePXFBEaHVcnfciArlX21e87I6Bt5GbIHBADN/jpsLH2b Fd7Q== X-Gm-Message-State: AOAM531mPY/hq/JEZdyQ6x+P24ee4DPtncVRQbSUoe+p7+YRuIeYNTJO Ym0yFwEXiorJJbRvtMNLSwr90VmOfVer3/Oi X-Google-Smtp-Source: ABdhPJzNAJ69SYxc2+3AnYnnzUZLzrBdhFYCN0Eo2OWt0+vefWkjttQl02GVRddyR0PVFYsl+4G9ng== X-Received: by 2002:adf:f684:: with SMTP id v4mr32245705wrp.387.1607994425766; Mon, 14 Dec 2020 17:07:05 -0800 (PST) Received: from [192.168.8.128] ([85.255.232.163]) by smtp.gmail.com with ESMTPSA id k10sm31006061wrq.38.2020.12.14.17.07.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 14 Dec 2020 17:07:04 -0800 (PST) To: Dave Chinner Cc: linux-block@vger.kernel.org, Jens Axboe , Christoph Hellwig , Matthew Wilcox , Ming Lei , Johannes Weiner , Alexander Viro , "Darrick J . Wong" , "Martin K . Petersen" , Jonathan Corbet , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, target-devel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-doc@vger.kernel.org References: <1d3cf86668e44b3a3d35b5dbe759a086a157e434.1607976425.git.asml.silence@gmail.com> <20201215005659.GF632069@dread.disaster.area> From: Pavel Begunkov Autocrypt: addr=asml.silence@gmail.com; prefer-encrypt=mutual; keydata= mQINBFmKBOQBEAC76ZFxLAKpDw0bKQ8CEiYJRGn8MHTUhURL02/7n1t0HkKQx2K1fCXClbps bdwSHrhOWdW61pmfMbDYbTj6ZvGRvhoLWfGkzujB2wjNcbNTXIoOzJEGISHaPf6E2IQx1ik9 6uqVkK1OMb7qRvKH0i7HYP4WJzYbEWVyLiAxUj611mC9tgd73oqZ2pLYzGTqF2j6a/obaqha +hXuWTvpDQXqcOZJXIW43atprH03G1tQs7VwR21Q1eq6Yvy2ESLdc38EqCszBfQRMmKy+cfp W3U9Mb1w0L680pXrONcnlDBCN7/sghGeMHjGKfNANjPc+0hzz3rApPxpoE7HC1uRiwC4et83 CKnncH1l7zgeBT9Oa3qEiBlaa1ZCBqrA4dY+z5fWJYjMpwI1SNp37RtF8fKXbKQg+JuUjAa9 Y6oXeyEvDHMyJYMcinl6xCqCBAXPHnHmawkMMgjr3BBRzODmMr+CPVvnYe7BFYfoajzqzq+h EyXSl3aBf0IDPTqSUrhbmjj5OEOYgRW5p+mdYtY1cXeK8copmd+fd/eTkghok5li58AojCba jRjp7zVOLOjDlpxxiKhuFmpV4yWNh5JJaTbwCRSd04sCcDNlJj+TehTr+o1QiORzc2t+N5iJ NbILft19Izdn8U39T5oWiynqa1qCLgbuFtnYx1HlUq/HvAm+kwARAQABtDFQYXZlbCBCZWd1 bmtvdiAoc2lsZW5jZSkgPGFzbWwuc2lsZW5jZUBnbWFpbC5jb20+iQJOBBMBCAA4FiEE+6Ju PTjTbx479o3OWt5b1Glr+6UFAlmKBOQCGwMFCwkIBwIGFQgJCgsCBBYCAwECHgECF4AACgkQ Wt5b1Glr+6WxZA//QueaKHzgdnOikJ7NA/Vq8FmhRlwgtP0+E+w93kL+ZGLzS/cUCIjn2f4Q Mcutj2Neg0CcYPX3b2nJiKr5Vn0rjJ/suiaOa1h1KzyNTOmxnsqE5fmxOf6C6x+NKE18I5Jy xzLQoktbdDVA7JfB1itt6iWSNoOTVcvFyvfe5ggy6FSCcP+m1RlR58XxVLH+qlAvxxOeEr/e aQfUzrs7gqdSd9zQGEZo0jtuBiB7k98t9y0oC9Jz0PJdvaj1NZUgtXG9pEtww3LdeXP/TkFl HBSxVflzeoFaj4UAuy8+uve7ya/ECNCc8kk0VYaEjoVrzJcYdKP583iRhOLlZA6HEmn/+Gh9 4orG67HNiJlbFiW3whxGizWsrtFNLsSP1YrEReYk9j1SoUHHzsu+ZtNfKuHIhK0sU07G1OPN 2rDLlzUWR9Jc22INAkhVHOogOcc5ajMGhgWcBJMLCoi219HlX69LIDu3Y34uIg9QPZIC2jwr 24W0kxmK6avJr7+n4o8m6sOJvhlumSp5TSNhRiKvAHB1I2JB8Q1yZCIPzx+w1ALxuoWiCdwV M/azguU42R17IuBzK0S3hPjXpEi2sK/k4pEPnHVUv9Cu09HCNnd6BRfFGjo8M9kZvw360gC1 reeMdqGjwQ68o9x0R7NBRrtUOh48TDLXCANAg97wjPoy37dQE7e5Ag0EWYoE5AEQAMWS+aBV IJtCjwtfCOV98NamFpDEjBMrCAfLm7wZlmXy5I6o7nzzCxEw06P2rhzp1hIqkaab1kHySU7g dkpjmQ7Jjlrf6KdMP87mC/Hx4+zgVCkTQCKkIxNE76Ff3O9uTvkWCspSh9J0qPYyCaVta2D1 Sq5HZ8WFcap71iVO1f2/FEHKJNz/YTSOS/W7dxJdXl2eoj3gYX2UZNfoaVv8OXKaWslZlgqN jSg9wsTv1K73AnQKt4fFhscN9YFxhtgD/SQuOldE5Ws4UlJoaFX/yCoJL3ky2kC0WFngzwRF Yo6u/KON/o28yyP+alYRMBrN0Dm60FuVSIFafSqXoJTIjSZ6olbEoT0u17Rag8BxnxryMrgR dkccq272MaSS0eOC9K2rtvxzddohRFPcy/8bkX+t2iukTDz75KSTKO+chce62Xxdg62dpkZX xK+HeDCZ7gRNZvAbDETr6XI63hPKi891GeZqvqQVYR8e+V2725w+H1iv3THiB1tx4L2bXZDI DtMKQ5D2RvCHNdPNcZeldEoJwKoA60yg6tuUquvsLvfCwtrmVI2rL2djYxRfGNmFMrUDN1Xq F3xozA91q3iZd9OYi9G+M/OA01husBdcIzj1hu0aL+MGg4Gqk6XwjoSxVd4YT41kTU7Kk+/I 5/Nf+i88ULt6HanBYcY/+Daeo/XFABEBAAGJAjYEGAEIACAWIQT7om49ONNvHjv2jc5a3lvU aWv7pQUCWYoE5AIbDAAKCRBa3lvUaWv7pfmcEACKTRQ28b1y5ztKuLdLr79+T+LwZKHjX++P 4wKjEOECCcB6KCv3hP+J2GCXDOPZvdg/ZYZafqP68Yy8AZqkfa4qPYHmIdpODtRzZSL48kM8 LRzV8Rl7J3ItvzdBRxf4T/Zseu5U6ELiQdCUkPGsJcPIJkgPjO2ROG/ZtYa9DvnShNWPlp+R uPwPccEQPWO/NP4fJl2zwC6byjljZhW5kxYswGMLBwb5cDUZAisIukyAa8Xshdan6C2RZcNs rB3L7vsg/R8UCehxOH0C+NypG2GqjVejNZsc7bgV49EOVltS+GmGyY+moIzxsuLmT93rqyII 5rSbbcTLe6KBYcs24XEoo49Zm9oDA3jYvNpeYD8rDcnNbuZh9kTgBwFN41JHOPv0W2FEEWqe JsCwQdcOQ56rtezdCJUYmRAt3BsfjN3Jn3N6rpodi4Dkdli8HylM5iq4ooeb5VkQ7UZxbCWt UVMKkOCdFhutRmYp0mbv2e87IK4erwNHQRkHUkzbsuym8RVpAZbLzLPIYK/J3RTErL6Z99N2 m3J6pjwSJY/zNwuFPs9zGEnRO4g0BUbwGdbuvDzaq6/3OJLKohr5eLXNU3JkT+3HezydWm3W OPhauth7W0db74Qd49HXK0xe/aPrK+Cp+kU1HRactyNtF8jZQbhMCC8vMGukZtWaAwpjWiiH bA== Subject: Re: [PATCH v1 4/6] block/psi: remove PSI annotations from direct IO Message-ID: Date: Tue, 15 Dec 2020 01:03:45 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: <20201215005659.GF632069@dread.disaster.area> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 15/12/2020 00:56, Dave Chinner wrote: > On Tue, Dec 15, 2020 at 12:20:23AM +0000, Pavel Begunkov wrote: >> As reported, we must not do pressure stall information accounting for >> direct IO, because otherwise it tells that it's thrashing a page when >> actually doing IO on hot data. >> >> Apparently, bio_iov_iter_get_pages() is used only by paths doing direct >> IO, so just make it avoid setting BIO_WORKINGSET, it also saves us CPU >> cycles on doing that. For fs/direct-io.c just clear the flag before >> submit_bio(), it's not of much concern performance-wise. >> >> Reported-by: Christoph Hellwig >> Suggested-by: Christoph Hellwig >> Suggested-by: Johannes Weiner >> Signed-off-by: Pavel Begunkov >> --- >> block/bio.c | 25 ++++++++++++++++--------- >> fs/direct-io.c | 2 ++ >> 2 files changed, 18 insertions(+), 9 deletions(-) > ..... >> @@ -1099,6 +1103,9 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter) >> * fit into the bio, or are requested in @iter, whatever is smaller. If >> * MM encounters an error pinning the requested pages, it stops. Error >> * is returned only if 0 pages could be pinned. >> + * >> + * It also doesn't set BIO_WORKINGSET, so is intended for direct IO. If used >> + * otherwise the caller is responsible to do that to keep PSI happy. >> */ >> int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) >> { >> diff --git a/fs/direct-io.c b/fs/direct-io.c >> index d53fa92a1ab6..914a7f600ecd 100644 >> --- a/fs/direct-io.c >> +++ b/fs/direct-io.c >> @@ -426,6 +426,8 @@ static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio) >> unsigned long flags; >> >> bio->bi_private = dio; >> + /* PSI is only for paging IO */ >> + bio_clear_flag(bio, BIO_WORKINGSET); > > Why only do this for the old direct IO path? Why isn't this > necessary for the iomap DIO path? It's in the description. In short, block and iomap dio use bio_iov_iter_get_pages(), which with this patch doesn't use [__]bio_add_page() and so doesn't set the flag. -- Pavel Begunkov