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 52B28C77B61 for ; Sun, 16 Apr 2023 18:12:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 89FC36B0072; Sun, 16 Apr 2023 14:12:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 850136B0074; Sun, 16 Apr 2023 14:12:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7177A6B0075; Sun, 16 Apr 2023 14:12:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 62A906B0072 for ; Sun, 16 Apr 2023 14:12:02 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 34975120135 for ; Sun, 16 Apr 2023 18:12:02 +0000 (UTC) X-FDA: 80688048084.12.4629543 Received: from mail-yw1-f170.google.com (mail-yw1-f170.google.com [209.85.128.170]) by imf13.hostedemail.com (Postfix) with ESMTP id 2AAC520007 for ; Sun, 16 Apr 2023 18:11:59 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=google.com header.s=20221208 header.b=woSRwUxu; spf=pass (imf13.hostedemail.com: domain of hughd@google.com designates 209.85.128.170 as permitted sender) smtp.mailfrom=hughd@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1681668720; a=rsa-sha256; cv=none; b=DvdJ+6yyDfcqWaENGs+MK66U4cgnyk70BOI4FCvpTKfXfk3Hzz6l00kgTvOAdAB3hi0uPG 5lx0ydV5YImuPCh+s05jo2T3kXkYw0iK8I/zEAAM/kv4/IziqhN6qzanPYmPTUT8AhA4lu YDK4w1ZgiPtYmVqjYaDKz4czg8NM2Fo= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=google.com header.s=20221208 header.b=woSRwUxu; spf=pass (imf13.hostedemail.com: domain of hughd@google.com designates 209.85.128.170 as permitted sender) smtp.mailfrom=hughd@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1681668720; h=from:from: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=LVJOhu0619OErP99xlPd4ihejbaRkAObRsbcnMFMEhQ=; b=n6nsc/u7e/05VEdARFeHN2Axxcg6p6wH44KTcdn4LvzJWlXNvYY/inP0/r/7DBfShi3LoW u/rdKXN58OvWEOMQTwUA9jY6mUKfSFoUBBUcyms8c3oV2eEDFz6BVlzfg8pl7V1ksWvv2q 0wjKz5lD5BC7blPZZfSg2FHnAfqtgQ4= Received: by mail-yw1-f170.google.com with SMTP id 00721157ae682-54fb615ac3dso184397627b3.2 for ; Sun, 16 Apr 2023 11:11:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1681668719; x=1684260719; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:from:to:cc:subject:date:message-id:reply-to; bh=LVJOhu0619OErP99xlPd4ihejbaRkAObRsbcnMFMEhQ=; b=woSRwUxuBadaYtz8Pla6HnY8OWT2Z6oLbv+IvJWJeFu7vl5IQgCqhJN9QW7j5/A8Ag Pnp0Moej9pT7JgW8tudH+yEzBUktIU4ioEkl0OO35HygM0IqCZWiph5WUYaiQP7GNxYE BcgYQV664/sYtXJroRKzXsITY7jTTPQUL/KzHaK/Iqz4JWfWRn/u4135QDVlSgHXlz1X X2iX0pcLJDn8kw1qlrq0JIqbpLnFN+aGhQn5GjLAP5/+v8T60MHc1c5lS46Ws3JX6Ie2 SR26zLTEOJMJNoPwgYukr9mQU3OL5Vks7gyt1HG1/eCYMNm7+uGDuWYwkrUYT2b06rn1 3ZmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681668719; x=1684260719; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=LVJOhu0619OErP99xlPd4ihejbaRkAObRsbcnMFMEhQ=; b=KXITnRef5iMAlvNE8ihM8XAuVjX+rohT5dc1M3KA5H5buKWkq5iz+53c3DE/IBYRVx HotTL/Wci41SAJN1j/U3lzLvTzwkwrQD7QnycT9lOiWsWHHPTWNtXQRBBeEBhSfDLJch iFlwzlJGUSMVsvGeQIP5YbBbGUEi5T/j3EHqCH0olm+n0qbHFG0dtX9csdn0x+WyvYaI rtFMCXUF/fzJoWxt8ITqEZiEL3Y8VaddGd1TOpm3tNA4IKcBw49jQ675F6ECvaWX0ge6 WupvqehwAbT0+KnDoDi7eeHq0Qs3vHpVuD4PYcmjrBToXaxleUVM1qDGh0rwwVkGDpiO Rl2g== X-Gm-Message-State: AAQBX9eQhXYXuxTUILaApomXoOr5u2YvZft/Qy4Rcy85OBZY/oKA6MU3 nsNZhvhlcuNcK38Y6f92kPUcow== X-Google-Smtp-Source: AKy350bXCNF1WdQWBeDDtbhUdV1w3MyrNNNENEJZGG7rSYcaEKYB0vPKGwv0o3fMAWWvdfv66tXB5A== X-Received: by 2002:a81:6c56:0:b0:551:805d:6f7b with SMTP id h83-20020a816c56000000b00551805d6f7bmr7528281ywc.0.1681668719039; Sun, 16 Apr 2023 11:11:59 -0700 (PDT) Received: from ripple.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id l31-20020a81ad5f000000b00545a0818483sm2636333ywk.19.2023.04.16.11.11.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 16 Apr 2023 11:11:58 -0700 (PDT) Date: Sun, 16 Apr 2023 11:11:49 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@ripple.attlocal.net To: Andrew Morton cc: Zi Yan , Zi Yan , "Matthew Wilcox (Oracle)" , Yang Shi , Yu Zhao , linux-mm@kvack.org, "Kirill A . Shutemov" , Ryan Roberts , =?ISO-8859-15?Q?Michal_Koutn=FD?= , Roman Gushchin , Zach O'Keefe , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v3 0/7] Split a folio to any lower order folios In-Reply-To: <20230404144727.e613116684dbd65a4b4745c1@linux-foundation.org> Message-ID: <49ee481e-452f-61c7-2da5-28de2cf3de2@google.com> References: <20230403201839.4097845-1-zi.yan@sent.com> <20230404144727.e613116684dbd65a4b4745c1@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Rspam-User: X-Rspamd-Queue-Id: 2AAC520007 X-Rspamd-Server: rspam01 X-Stat-Signature: 14ukqii1cjjhwiqbp83y7uufuxuoa7ba X-HE-Tag: 1681668719-210334 X-HE-Meta: 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 xrrztPJ2 x2QOd5sZIfyLIQj/y3v8xqEB1TYNRh9Pxj3OlaGcHgCYE8Eiyms4Gr9ln8XemgCcWWyujQ6snbv6xJEoIld9UV8Lvrn6CfRF2joBI8g5eltM+G3zAwy1guDv9boEN4c6hvLZ8AhoZvNJJq7hpEIc2/e4VfHFgaTsxDROso/4RMhCtSwyTgRkbbxnXCGybCMOy4l7EPVLfH91r1l04eNLReR0m0LP00BJ16FLhO+0EWRR0anGe+rEqUF+fYL5Db1F0e8P6LVF62MJd7gVi4dxDNyD42pj+I6cQGEaddJ/s/SRMacH6O2wBfZRXwMFXB+R9Bm/y/wiDF3IeLv8zhvpfSuhNNvMQOU0JJnZ80H8HWUyDD+rQW0iQ2hpmsmzae5Kq+pTMiuNKF9VTnOZZMPVVXE08VehkOjk4D4KGD1zC0JBVZqQhvdXSvygj5A== 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: On Tue, 4 Apr 2023, Andrew Morton wrote: > On Mon, 3 Apr 2023 16:18:32 -0400 Zi Yan wrote: > > > File folio supports any order and people would like to support flexible orders > > for anonymous folio[1] too. Currently, split_huge_page() only splits a huge > > page to order-0 pages, but splitting to orders higher than 0 is also useful. > > This patchset adds support for splitting a huge page to any lower order pages > > and uses it during file folio truncate operations. > > This series (and its v1 & v2) don't appear to have much in the way of > detailed review. As it's at v3 and has been fairly stable I'll queue > it up for some testing now, but I do ask that some reviewers go through > it please. Andrew, please don't let this series drift into 6.4-rc1. I've seen a bug or two (I'll point out in response to those patches), but overall I don't see what the justification for the series is: done because it could be done, it seems to me, but liable to add surprises. The cover letter says "splitting to orders higher than 0 is also useful", but it's not clear why; and the infrastructure provided seems unsuited to the one use provided - I'll say more on that truncation patch. Thanks, Hugh