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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1E9BC02180 for ; Wed, 15 Jan 2025 16:41:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6F8F0280002; Wed, 15 Jan 2025 11:41:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6AA4B280001; Wed, 15 Jan 2025 11:41:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5230D280002; Wed, 15 Jan 2025 11:41:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 30DCF280001 for ; Wed, 15 Jan 2025 11:41:50 -0500 (EST) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id C05C8C154E for ; Wed, 15 Jan 2025 16:41:49 +0000 (UTC) X-FDA: 83010252738.25.DC2866B Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) by imf03.hostedemail.com (Postfix) with ESMTP id 89EA32000C for ; Wed, 15 Jan 2025 16:41:47 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Fe2m8h9m; dmarc=none; spf=pass (imf03.hostedemail.com: domain of groeck7@gmail.com designates 209.85.214.177 as permitted sender) smtp.mailfrom=groeck7@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1736959307; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=vp92K/CnscuW1Z8Iv1vO69wSCVbFsnQzXlMk7515To4=; b=ghWE5uo+PbBb4ghJLr0vwH08UZbajS3rwN5R/BFIJ/tVQviHiujFJxypxW5w92nDy36Hit 1b+9XfNk76cNX6s6FhcibAAn95hZplMuJ53Ago4L6bG5OCkHEk+CgpaneKNl+QnJZm/LOE UpGtNP3j00/670RsWrUWk5J6Lyb1Zj8= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1736959307; a=rsa-sha256; cv=none; b=w8AlaaUT2DOtyw7Lkm3Kt33cjxGiXOG81FNN0qs1SHcouvhqiMfcox6WWRthLGwqHB6FZn qBDBYkNpHjhuQFKs+EtW8Rt0G3ZpmCxZ05rx8QmaViEZ/h8Wiv4Co685X3bgg8Ey8ttu6W GWkQmXMS+cJ6AoQ8pHP/yU6gzLxSF08= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Fe2m8h9m; dmarc=none; spf=pass (imf03.hostedemail.com: domain of groeck7@gmail.com designates 209.85.214.177 as permitted sender) smtp.mailfrom=groeck7@gmail.com Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-21619108a6bso124493575ad.3 for ; Wed, 15 Jan 2025 08:41:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1736959306; x=1737564106; darn=kvack.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:sender:from:to:cc:subject:date:message-id:reply-to; bh=vp92K/CnscuW1Z8Iv1vO69wSCVbFsnQzXlMk7515To4=; b=Fe2m8h9m5ObQEmbusHDYqHtgm+lPbzrIysTkEfwa2ELIOOMkfwT96icH/7O/lDjuN7 YdEGxrlD8C6yF6mudeCWzhtDDnrGA8fZq83OQAIopiUaYid4i/42lSwGo0U+uBP0p3t7 IqBEdScigVcCgGr6m2CyKYADWmurXEeUvuzlVnMkkZvOyENcA8Miu8MhWoSsMoNmic43 kqv2bx46VWDB31d88ESdwuKwRrdaVUZSa4fGqnn30gtqPoJvUKvlypbahl4ddWnnIlY1 gKgoH9UlaGnQ0mTS0HWIxnNxkL/nlI5yx8HLgxT05ZF2OjQous5N6fC5sTive9AEqYfT eAlw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736959306; x=1737564106; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:sender:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=vp92K/CnscuW1Z8Iv1vO69wSCVbFsnQzXlMk7515To4=; b=d8JLaTXR5SDLexOcdyx9CbxZqnqnSG7D+luvspRGKnoQ60zPCktW7/kjDz1YGoWHDo SPaFXxECJYyBKvGb6Rc3VWNYmseXpKzBYiWkL2YGyFEE42SR3Ej87tlEFLx43eTOestF wC4aV9K0BBcrnTy24DFWRg8683kpr7ytWn+03M7wlrLV/zR/dm4Z+geecp5vU2zkvFYe A3G4+rFLVm7wa/VXeAFgwi3GmMVGSefAFLamsm0wSakwZgW7EifWsygOW0PtnbZVVi9R a7u4T+z03be28vxID0S/sAQIIRjTZCVh5JeNyNzV7fcJaJFQAHMUMKyDtA71OEpahQ5F KVPg== X-Forwarded-Encrypted: i=1; AJvYcCWlK7G+BkuV2HGyT34Ed5g85hONjwySJXbz7y1yXYX8MvhSaDh9qM+i4Zg5Xpo0CrRXvzMtMOr3gg==@kvack.org X-Gm-Message-State: AOJu0Yw2gJJ1Q5o9+RYJka7rckbWeG7KCZmQx9mlKgdpVNCSt8WqGgid T6BrgrSHsPrfA8c1JNx3MyiFY0sRzi7a57cHhrHrrWjA+xdwygQg X-Gm-Gg: ASbGncsYxfsjzy39X0aV4++IEIubL4lrMFOIHVHc6fAK0FnRbnz3xIfm0LQqvCRWjZb tJaAh7YZ7bPY92gJyXarOmcTsFk4dv6Gr6B8t8xNdDlzrSMOkQTOfq3Q0wu3A1ir7qJXFZGuAXI woNJmLqhGedIbXljSOxkqORej46Ke1wkOkBCAktoCgK3F2q+b1/XuVS1fwbndD05WYmZdUCVIBx 9Uh8Hmr2pK5fCoicUcbgEYTFDd7Tg+F6LIHbgl3hiQ0/AHzmfK9mEKlSKaHbvAep5eOkl1TFb6Y ipfMGBRxuCorvT1M+x5GdVgpxnwdqA== X-Google-Smtp-Source: AGHT+IHgyOemxtdmjl2Wh5yzfKZLW/+OLECB3oHCCC6H9TCj375njznMOdV+kghbjISc0pXTNZk11Q== X-Received: by 2002:a05:6a00:4486:b0:729:597:4faa with SMTP id d2e1a72fcca58-72d21fb1d72mr41332490b3a.16.1736959305824; Wed, 15 Jan 2025 08:41:45 -0800 (PST) Received: from ?IPV6:2600:1700:e321:62f0:da43:aeff:fecc:bfd5? ([2600:1700:e321:62f0:da43:aeff:fecc:bfd5]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-72d405493acsm9294034b3a.28.2025.01.15.08.41.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 15 Jan 2025 08:41:45 -0800 (PST) Message-ID: <0e5dc5f1-c2c2-4893-902b-4677c21a38c0@roeck-us.net> Date: Wed, 15 Jan 2025 08:41:43 -0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/page-writeback: Consolidate wb_thresh bumping logic into __wb_calc_thresh To: Jan Kara Cc: Jim Zhao , akpm@linux-foundation.org, willy@infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20241121100539.605818-1-jimzhao.ai@gmail.com> <64a44636-16ec-4a10-aeb6-e327b7f989c2@roeck-us.net> Content-Language: en-US From: Guenter Roeck Autocrypt: addr=linux@roeck-us.net; keydata= xsFNBE6H1WcBEACu6jIcw5kZ5dGeJ7E7B2uweQR/4FGxH10/H1O1+ApmcQ9i87XdZQiB9cpN RYHA7RCEK2dh6dDccykQk3bC90xXMPg+O3R+C/SkwcnUak1UZaeK/SwQbq/t0tkMzYDRxfJ7 nyFiKxUehbNF3r9qlJgPqONwX5vJy4/GvDHdddSCxV41P/ejsZ8PykxyJs98UWhF54tGRWFl 7i1xvaDB9lN5WTLRKSO7wICuLiSz5WZHXMkyF4d+/O5ll7yz/o/JxK5vO/sduYDIlFTvBZDh gzaEtNf5tQjsjG4io8E0Yq0ViobLkS2RTNZT8ICq/Jmvl0SpbHRvYwa2DhNsK0YjHFQBB0FX IdhdUEzNefcNcYvqigJpdICoP2e4yJSyflHFO4dr0OrdnGLe1Zi/8Xo/2+M1dSSEt196rXaC kwu2KgIgmkRBb3cp2vIBBIIowU8W3qC1+w+RdMUrZxKGWJ3juwcgveJlzMpMZNyM1jobSXZ0 VHGMNJ3MwXlrEFPXaYJgibcg6brM6wGfX/LBvc/haWw4yO24lT5eitm4UBdIy9pKkKmHHh7s jfZJkB5fWKVdoCv/omy6UyH6ykLOPFugl+hVL2Prf8xrXuZe1CMS7ID9Lc8FaL1ROIN/W8Vk BIsJMaWOhks//7d92Uf3EArDlDShwR2+D+AMon8NULuLBHiEUQARAQABzTJHdWVudGVyIFJv ZWNrIChMaW51eCBhY2NvdW50KSA8bGludXhAcm9lY2stdXMubmV0PsLBgQQTAQIAKwIbAwYL CQgHAwIGFQgCCQoLBBYCAwECHgECF4ACGQEFAlVcphcFCRmg06EACgkQyx8mb86fmYFg0RAA nzXJzuPkLJaOmSIzPAqqnutACchT/meCOgMEpS5oLf6xn5ySZkl23OxuhpMZTVX+49c9pvBx hpvl5bCWFu5qC1jC2eWRYU+aZZE4sxMaAGeWenQJsiG9lP8wkfCJP3ockNu0ZXXAXwIbY1O1 c+l11zQkZw89zNgWgKobKzrDMBFOYtAh0pAInZ9TSn7oA4Ctejouo5wUugmk8MrDtUVXmEA9 7f9fgKYSwl/H7dfKKsS1bDOpyJlqhEAH94BHJdK/b1tzwJCFAXFhMlmlbYEk8kWjcxQgDWMu GAthQzSuAyhqyZwFcOlMCNbAcTSQawSo3B9yM9mHJne5RrAbVz4TWLnEaX8gA5xK3uCNCeyI sqYuzA4OzcMwnnTASvzsGZoYHTFP3DQwf2nzxD6yBGCfwNGIYfS0i8YN8XcBgEcDFMWpOQhT Pu3HeztMnF3HXrc0t7e5rDW9zCh3k2PA6D2NV4fews9KDFhLlTfCVzf0PS1dRVVWM+4jVl6l HRIAgWp+2/f8dx5vPc4Ycp4IsZN0l1h9uT7qm1KTwz+sSl1zOqKD/BpfGNZfLRRxrXthvvY8 BltcuZ4+PGFTcRkMytUbMDFMF9Cjd2W9dXD35PEtvj8wnEyzIos8bbgtLrGTv/SYhmPpahJA l8hPhYvmAvpOmusUUyB30StsHIU2LLccUPPOwU0ETofVZwEQALlLbQeBDTDbwQYrj0gbx3bq 7kpKABxN2MqeuqGr02DpS9883d/t7ontxasXoEz2GTioevvRmllJlPQERVxM8gQoNg22twF7 pB/zsrIjxkE9heE4wYfN1AyzT+AxgYN6f8hVQ7Nrc9XgZZe+8IkuW/Nf64KzNJXnSH4u6nJM J2+Dt274YoFcXR1nG76Q259mKwzbCukKbd6piL+VsT/qBrLhZe9Ivbjq5WMdkQKnP7gYKCAi pNVJC4enWfivZsYupMd9qn7Uv/oCZDYoBTdMSBUblaLMwlcjnPpOYK5rfHvC4opxl+P/Vzyz 6WC2TLkPtKvYvXmdsI6rnEI4Uucg0Au/Ulg7aqqKhzGPIbVaL+U0Wk82nz6hz+WP2ggTrY1w ZlPlRt8WM9w6WfLf2j+PuGklj37m+KvaOEfLsF1v464dSpy1tQVHhhp8LFTxh/6RWkRIR2uF I4v3Xu/k5D0LhaZHpQ4C+xKsQxpTGuYh2tnRaRL14YMW1dlI3HfeB2gj7Yc8XdHh9vkpPyuT nY/ZsFbnvBtiw7GchKKri2gDhRb2QNNDyBnQn5mRFw7CyuFclAksOdV/sdpQnYlYcRQWOUGY HhQ5eqTRZjm9z+qQe/T0HQpmiPTqQcIaG/edgKVTUjITfA7AJMKLQHgp04Vylb+G6jocnQQX JqvvP09whbqrABEBAAHCwWUEGAECAA8CGwwFAlVcpi8FCRmg08MACgkQyx8mb86fmYHNRQ/+ J0OZsBYP4leJvQF8lx9zif+v4ZY/6C9tTcUv/KNAE5leyrD4IKbnV4PnbrVhjq861it/zRQW cFpWQszZyWRwNPWUUz7ejmm9lAwPbr8xWT4qMSA43VKQ7ZCeTQJ4TC8kjqtcbw41SjkjrcTG wF52zFO4bOWyovVAPncvV9eGA/vtnd3xEZXQiSt91kBSqK28yjxAqK/c3G6i7IX2rg6pzgqh hiH3/1qM2M/LSuqAv0Rwrt/k+pZXE+B4Ud42hwmMr0TfhNxG+X7YKvjKC+SjPjqp0CaztQ0H nsDLSLElVROxCd9m8CAUuHplgmR3seYCOrT4jriMFBtKNPtj2EE4DNV4s7k0Zy+6iRQ8G8ng QjsSqYJx8iAR8JRB7Gm2rQOMv8lSRdjva++GT0VLXtHULdlzg8VjDnFZ3lfz5PWEOeIMk7Rj trjv82EZtrhLuLjHRCaG50OOm0hwPSk1J64R8O3HjSLdertmw7eyAYOo4RuWJguYMg5DRnBk WkRwrSuCn7UG+qVWZeKEsFKFOkynOs3pVbcbq1pxbhk3TRWCGRU5JolI4ohy/7JV1TVbjiDI HP/aVnm6NC8of26P40Pg8EdAhajZnHHjA7FrJXsy3cyIGqvg9os4rNkUWmrCfLLsZDHD8FnU mDW4+i+XlNFUPUYMrIKi9joBhu18ssf5i5Q= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: oxc6srugur8yh45qxgtyqcih495fu4a3 X-Rspamd-Queue-Id: 89EA32000C X-Rspam-User: X-Rspamd-Server: rspam01 X-HE-Tag: 1736959307-896673 X-HE-Meta: U2FsdGVkX182jA2d43VAEf6Ga4+Cnj+BApI2mRTHVHcQldtUssCY3wXYgrPOAXQJXLz2T0+thvHl5LOt0gBTM3rgyhrh+YKqLs12e7MXHgtt3et8dnVoY6OTzrt2j2TCVGYdhDA1fLKKSsB3JDIR/dN4FNlWUFdNpZJl+lOIAoGT0jFzZDA0F/ATWLsI9MFBJupgAq42koLK38mZ0T/53DVb5gKWlgfVKvy7n02af8j5GHgb4KjXtGavlwgV2WRjhPCk5CFy5QchM/gI8qkTGkd0hpFGMtXpmYIOB8ZEmAx0gNDCPKxX8z6ZM/s1fmnvoVbRrVEx/O0jn+y/DC954d9+vHKgQQRT6MXWybL4OPXsd6htIUz9WFpBjWHribxPND/yxmgfl7dP+YaSalQNz9oLdflr7S+CZ6LoZEsMivGQ++cWiQ/da/kSmUNrxfmwCpiAU1pChABxXVHo28MiVkE0X+VvnOpU83jy3xVN//lwuN07gKmeauWJo0i8c8cgtmr/mqMsWT6dEAIqaKLbHEEAO0ihLOqaEMDCDJ23ZLcaD7o3G+A5G7I4P8xMS3mRAeIcjzAAHknYCO/SoLT4sZGqfaUCgFr2DgcoEaMB68u37QNsrU31dsTOJKdbyZcELhTY5h/M2gnWSnfxaW9DoMaiZHk4wbADEAMl8GNS4x7o36Ar3igmlCXaFPTbVJpho2mwXTCvsEIRo/Ta4G8K/dzKQ5HsEItT+JwD4zBSz2PJ3f/II967/XFxXw9Sj1pNOWr+iHS6EvPWFeRcJcbXBCYmCoaJ2DeDsmYY64evyHcfPJsjB8eEMf+iIjrXJlPQAf9icnfOZ0W7cOPf0yrCQnkah7YtS+A5R426v+GPeR3JEUwZQhSI+0LNe/Ismi4xTiZI6j96Fif6VCphIiwMYI46lizP994lO+bxqtDyzx66yOrOfE2DzNBipCPKiOClTHuSLVep2uaF1JtH8cm EA+Ez0/0 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 1/15/25 08:07, Jan Kara wrote: > On Tue 14-01-25 07:01:08, Guenter Roeck wrote: >> On 1/14/25 05:19, Jan Kara wrote: >>> On Mon 13-01-25 15:05:25, Guenter Roeck wrote: >>>> On Thu, Nov 21, 2024 at 06:05:39PM +0800, Jim Zhao wrote: >>>>> Address the feedback from "mm/page-writeback: raise wb_thresh to prevent >>>>> write blocking with strictlimit"(39ac99852fca98ca44d52716d792dfaf24981f53). >>>>> The wb_thresh bumping logic is scattered across wb_position_ratio, >>>>> __wb_calc_thresh, and wb_update_dirty_ratelimit. For consistency, >>>>> consolidate all wb_thresh bumping logic into __wb_calc_thresh. >>>>> >>>>> Reviewed-by: Jan Kara >>>>> Signed-off-by: Jim Zhao >>>> >>>> This patch triggers a boot failure with one of my 'sheb' boot tests. >>>> It is seen when trying to boot from flash (mtd). The log says >>>> >>>> ... >>>> Starting network: 8139cp 0000:00:02.0 eth0: link down >>>> udhcpc: started, v1.33.0 >>>> EXT2-fs (mtdblock3): error: ext2_check_folio: bad entry in directory #363: : directory entry across blocks - offset=0, inode=27393, rec_len=3072, name_len=2 >>>> udhcpc: sending discover >>>> udhcpc: sending discover >>>> udhcpc: sending discover >>>> EXT2-fs (mtdblock3): error: ext2_check_folio: bad entry in directory #363: : directory entry across blocks - offset=0, inode=27393, rec_len=3072, name_len=2 >>> >>> Thanks for report! Uh, I have to say I'm very confused by this. It is clear >>> than when ext2 detects the directory corruption (we fail checking directory >>> inode 363 which is likely /etc/init.d/), the boot fails in interesting >>> ways. What is unclear is how the commit can possibly cause ext2 directory >>> corruption. If you didn't verify reverting the commit fixes the issue, I'd >>> be suspecting bad bisection but that obviously isn't the case :-) >>> >>> Ext2 is storing directory data in the page cache so at least it uses the >>> subsystem which the patch impacts but how writeback throttling can cause >>> ext2 directory corruption is beyond me. BTW, do you recreate the root >>> filesystem before each boot? How exactly? >> >> I use pre-built root file systems. For sheb, they are at >> https://github.com/groeck/linux-build-test/tree/master/rootfs/sheb > > Thanks. So the problematic directory is /usr/share/udhcpc/ where we > read apparently bogus metadata at the beginning of that directory. > >> I don't think this is related to ext2 itself. Booting an ext2 image from >> ata/ide drive works. > > Interesting this is specific to mtd. I'll read the patch carefully again if > something rings a bell. > Interesting. Is there some endianness issue, by any chance ? I only see the problem with sheb (big endian), not with sh (little endian). I'd suspect that it is an emulation bug, but it is odd that the problem did not show up before. Guenter