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=-14.8 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1, USER_IN_DEF_DKIM_WL autolearn=no 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 62AF3C433E9 for ; Mon, 1 Mar 2021 20:16:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E9D0C64DDF for ; Mon, 1 Mar 2021 20:16:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E9D0C64DDF Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4528A8D009D; Mon, 1 Mar 2021 15:16:44 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 403488D0063; Mon, 1 Mar 2021 15:16:44 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 319A98D009D; Mon, 1 Mar 2021 15:16:44 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0237.hostedemail.com [216.40.44.237]) by kanga.kvack.org (Postfix) with ESMTP id 1B40F8D0063 for ; Mon, 1 Mar 2021 15:16:44 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id DC90C81FC for ; Mon, 1 Mar 2021 20:16:43 +0000 (UTC) X-FDA: 77872413486.17.A63EEC0 Received: from mail-oi1-f182.google.com (mail-oi1-f182.google.com [209.85.167.182]) by imf08.hostedemail.com (Postfix) with ESMTP id 23CCE801A802 for ; Mon, 1 Mar 2021 20:16:19 +0000 (UTC) Received: by mail-oi1-f182.google.com with SMTP id d20so19415183oiw.10 for ; Mon, 01 Mar 2021 12:16:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:mime-version; bh=CpiE1pBrxa73ZoavNQfgfeEm27dty1Q76LBnbbf260Y=; b=HeZobEdHhxUthkkeiQ+zZFdYT0M1eBhINCAyAp+kaPBBn6NWOkA4YCfwK4HlNJ4iO+ y7kN2zEX9XByXD8cu0e3agyI1yx43wWMPa4zRq8RFygp2bxl7LENZKDcXqHphOL+lCkc QHP8WGdorrbiHzk6I3IS3qczMfznL23MF7Brb1N8Iabvuw1Dekh5ig3tq8tI0ui5OaOx JEaHPRUFLYaXLWBuVzCQeWftCHO3ssfEf+U6LcircvndN1y+qz1PEuitxjCuSYFtHYkc uLrCoq4vXlEPHKSixRFS6wEXydJbO8UB1gR3PUkiObLUOx+99bUV5BoHJj+/wA+UYFF3 BO9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version; bh=CpiE1pBrxa73ZoavNQfgfeEm27dty1Q76LBnbbf260Y=; b=qhqp4xAwJdC8bhvNcD2x7DszqM5wUxGk0c+xAT2uxaAfVbcujlr6dGnblLMuVJ+GUw vtj8PErvkszkmM0rUufX9mL8sGO4JOgN+ZmWkTsZNnAacZ2eKq/sB5KAt58CteE6FLUP lJQ4AblYb7PU2559Glge3VbMNBzQFuZfEx/6Hq5EquaLN2b5jTR0RalI6Dpw6uokw+iv 5J5pQhvSprdVwVGT0gnvtYU1zYA6s1nImh4K2YP46rlreow19wwSVMnTFShlvc/aB0ve +9lqCYSetmlZlGyW3kSR6gsSHncFc9o1WYasp4TvRu5SaY0rPbqYF/K7xHxUfjJE28hX IqGQ== X-Gm-Message-State: AOAM533QuTUVm+GAcNPGMcRfv9TKfHYQg3TZRJkmog/I7qC6eWUU6Qeq FMqtEKyo+xX9WT4tEy1dZToWzw== X-Google-Smtp-Source: ABdhPJyX7Z9XnpFyNuqpfqkjPIdufx/u4bzd7dwJJIfVixRVYr5mvebT1DMOwhkGk2hOtFa5zMskoQ== X-Received: by 2002:a05:6808:24d:: with SMTP id m13mr532829oie.165.1614629791975; Mon, 01 Mar 2021 12:16:31 -0800 (PST) Received: from eggly.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id t13sm4039319otp.42.2021.03.01.12.16.30 (version=TLS1 cipher=ECDHE-ECDSA-AES128-SHA bits=128/128); Mon, 01 Mar 2021 12:16:31 -0800 (PST) Date: Mon, 1 Mar 2021 12:16:19 -0800 (PST) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Yu Zhao cc: "Kirill A. Shutemov" , Matthew Wilcox , akpm@linux-foundation.org, alex.shi@linux.alibaba.com, vbabka@suse.cz, guro@fb.com, hannes@cmpxchg.org, hughd@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@kernel.org, vdavydov.dev@gmail.com Subject: Re: [PATCH v2 3/3] mm: use PF_ONLY_HEAD for PG_active and PG_unevictable In-Reply-To: Message-ID: References: <20210224084807.2179942-1-yuzhao@google.com> <20210226091718.2927291-1-yuzhao@google.com> <20210226091718.2927291-4-yuzhao@google.com> <20210226121314.GB2723601@casper.infradead.org> <20210301115007.mgw5vthgjoibnjf4@box> User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 23CCE801A802 X-Stat-Signature: tsjoqp1k8i8yh9spmq5mec4365ym8366 Received-SPF: none (google.com>: No applicable sender policy available) receiver=imf08; identity=mailfrom; envelope-from=""; helo=mail-oi1-f182.google.com; client-ip=209.85.167.182 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614629779-924809 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 Mon, 1 Mar 2021, Yu Zhao wrote: > On Mon, Mar 01, 2021 at 02:50:07PM +0300, Kirill A. Shutemov wrote: > > On Fri, Feb 26, 2021 at 12:13:14PM +0000, Matthew Wilcox wrote: > > > On Fri, Feb 26, 2021 at 02:17:18AM -0700, Yu Zhao wrote: > > > > All places but one test, set or clear PG_active and PG_unevictable on > > > > small or head pages. Use compound_head() explicitly for that singleton > > > > so the rest can rid of redundant compound_head(). > > > > > > How do you know it's only one place? I really wish you'd work with me > > > on folios. They make the compiler prove that it's not a tail page. > > > > +1 to this. > > > > The problem with compound_head() is systemic and ad-hoc solution to few > > page flags will only complicate the picture. > > Well, I call it an incremental improvement, and how exactly does it > complicate the picture? > > I see your point: you prefer a complete replacement. But my point is > not about the preference; it's about presenting an option: I'm not > saying we have to go with this series; I'm saying if you don't want > to wait, here is something quick but not perfect. +1 to this. Hugh