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 C296DCDDE70 for ; Wed, 23 Oct 2024 11:38:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 348DA6B007B; Wed, 23 Oct 2024 07:38:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2D24E6B0082; Wed, 23 Oct 2024 07:38:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 124F66B0088; Wed, 23 Oct 2024 07:38:37 -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 E0F486B007B for ; Wed, 23 Oct 2024 07:38:36 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id D519EA0980 for ; Wed, 23 Oct 2024 11:38:04 +0000 (UTC) X-FDA: 82704668592.07.209ADAF Received: from fout-a8-smtp.messagingengine.com (fout-a8-smtp.messagingengine.com [103.168.172.151]) by imf11.hostedemail.com (Postfix) with ESMTP id B60D54001A for ; Wed, 23 Oct 2024 11:38:13 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=shutemov.name header.s=fm1 header.b="b MYaD7n"; dkim=pass header.d=messagingengine.com header.s=fm3 header.b=F1zrF0cW; dmarc=none; spf=pass (imf11.hostedemail.com: domain of kirill@shutemov.name designates 103.168.172.151 as permitted sender) smtp.mailfrom=kirill@shutemov.name ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1729683476; a=rsa-sha256; cv=none; b=TMKXDXlWiTM8ezGMe66ubonO4V/jqLE91IDxs4/LUVr+D6cMgS/M1Gbf91PgrndVBEbZ2n SBPKuYy+wEXKPpgQswhy+C1t899KJkR/JkwjWY07aJV1HbGfyn3i5nG6Vrd8QkRI5PM21Y Zp16ZlrKOdQ0ZvjohIfAYF+r1uUQ8cg= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=shutemov.name header.s=fm1 header.b="b MYaD7n"; dkim=pass header.d=messagingengine.com header.s=fm3 header.b=F1zrF0cW; dmarc=none; spf=pass (imf11.hostedemail.com: domain of kirill@shutemov.name designates 103.168.172.151 as permitted sender) smtp.mailfrom=kirill@shutemov.name ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1729683476; 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=G6CUi21sJIgULg4YyxpP72kDdA8AWcHDBrNG6d45KA8=; b=IRB7M2oai3MTK/CZrazkxzUcWE88ot6H5/tqyhhwAfKSoVeJpJ9tDDyZaC9iAm27WfRxew JEPmNNzfMnlrpWwr/0OpQ8VA67cvId4o7cjFMU8WVqJoXeY2zlW7gIFMpQ5dKRQriTo0tO jgT55PI9GjF40lnqI0FASOv1sLiev5Y= Received: from phl-compute-03.internal (phl-compute-03.phl.internal [10.202.2.43]) by mailfout.phl.internal (Postfix) with ESMTP id E30CD13807A3; Wed, 23 Oct 2024 07:38:33 -0400 (EDT) Received: from phl-mailfrontend-01 ([10.202.2.162]) by phl-compute-03.internal (MEProxy); Wed, 23 Oct 2024 07:38:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov.name; h=cc:cc:content-type:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:subject:subject:to:to; s=fm1; t=1729683513; x= 1729769913; bh=G6CUi21sJIgULg4YyxpP72kDdA8AWcHDBrNG6d45KA8=; b=b MYaD7nEySPXh7O4/RcFrX+MizsCOUtTadpngQe0QdRJjqVSqF/jI+5/2HmBheKkt c5mCxMz8LDC+bttnTWAI600BShR5Gdx6d6lvhrw9f/0dVA7Y5K3hkGPD4KCXCyWf LhUUy6ygcjx6CqdoeexPsNUMk4VnyE+n1AQgXwGJ20bwMs/1JWxsCOlWX6l8O+pw Sxx4QQ4FV+zvVldo0zD62+/Wy+6XvLZ+kw1gVtaiUiWjYYkQW/4sY0lpfO2Jom2/ vsx53REiG/RgCrw6mRcT08/PyAqZVit3zrWbEPFiVmjIKkrtVl00Azvl7i59O/lW 7Mf0GGDFEvE862hbU4oDw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:subject:subject:to :to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm3; t=1729683513; x=1729769913; bh=G6CUi21sJIgULg4YyxpP72kDdA8A WcHDBrNG6d45KA8=; b=F1zrF0cW0VSFjM0x4dQO0iEG41G/dAsSFFHilHRv7sfu AIu+9rdB0V2od+a7vBO2r6ECptu354ukTLB5rQATGOKWCJ6lnqwcxqYHfqQVD2B3 q5KC+zGIaENAffEhKt7SjDFK2QCAenIO8+MMoHxlIyXc5/2+QekVZpD9KQ3lBAAI DZ51zkCSz9RSC33JW+RDSFouh4g/UzMV/UKQIwxMLjGduIlqbaJqSQIP7OFM8MxW +tXsB4Ific2k2oNbtWTN0b38GcTcfR0u5k0qMd/9nddciUeGFEMTkLI/yDphUt4X whWok8f/eeC/NW81aHwQMzeVsBR2DT/vxRzVfztvvw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeftddrvdeijedggeduucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdggtfgfnhhsuhgsshgtrhhisggvpdfu rfetoffkrfgpnffqhgenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnh htshculddquddttddmnecujfgurhepfffhvfevuffkfhggtggujgesthdtsfdttddtvden ucfhrhhomhepfdfmihhrihhllhcutedrucfuhhhuthgvmhhovhdfuceokhhirhhilhhlse hshhhuthgvmhhovhdrnhgrmhgvqeenucggtffrrghtthgvrhhnpeffvdevueetudfhhfff veelhfetfeevveekleevjeduudevvdduvdelteduvefhkeenucevlhhushhtvghrufhiii gvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehkihhrihhllhesshhhuhhtvghmohhv rdhnrghmvgdpnhgspghrtghpthhtohepudekpdhmohguvgepshhmthhpohhuthdprhgtph htthhopegurghvihgusehrvgguhhgrthdrtghomhdprhgtphhtthhopehlihhnuhigqdhk vghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqd hmmheskhhvrggtkhdrohhrghdprhgtphhtthhopegtghhrohhuphhssehvghgvrhdrkhgv rhhnvghlrdhorhhgpdhrtghpthhtohepgiekieeskhgvrhhnvghlrdhorhhgpdhrtghpth htoheplhhinhhugidqfhhsuggvvhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgt phhtthhopegrkhhpmheslhhinhhugidqfhhouhhnuggrthhiohhnrdhorhhgpdhrtghpth htohepfihilhhlhiesihhnfhhrrgguvggrugdrohhrghdprhgtphhtthhopehtjheskhgv rhhnvghlrdhorhhg X-ME-Proxy: Feedback-ID: ie3994620:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 23 Oct 2024 07:38:27 -0400 (EDT) Date: Wed, 23 Oct 2024 14:38:22 +0300 From: "Kirill A. Shutemov" To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, x86@kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , "Matthew Wilcox (Oracle)" , Tejun Heo , Zefan Li , Johannes Weiner , Michal =?utf-8?Q?Koutn=C3=BD?= , Jonathan Corbet , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen Subject: Re: [PATCH v1 04/17] mm: let _folio_nr_pages overlay memcg_data in first tail page Message-ID: References: <20240829165627.2256514-1-david@redhat.com> <20240829165627.2256514-5-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240829165627.2256514-5-david@redhat.com> X-Rspam-User: X-Stat-Signature: 8a58q9y5rf8jeowgtypeb4e8n9ktaic7 X-Rspamd-Queue-Id: B60D54001A X-Rspamd-Server: rspam02 X-HE-Tag: 1729683493-164351 X-HE-Meta: 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 uCS1PY60 kj6NpnV6Ioo3BREg0KiFJI/NE0+BnoORDmzdi/DcY7zjfPBK+ca38XQ7Rcb+wWjGTk1de2T4uWpgHRLiaRlsEI+HSu2ZYmd/m9fjuN+NrZPiKHEZmSprlZpRtAo+hIKdk/oZI14YAkvS95xmdWMjJYoy/JePEO3iTLi1+tSp2sPKlN7pZoN8FPu7QuLqezH+9/BilZ4P+NoIJrNvyaDYxPb8fFDG7mnd5J3enDnb85s/x0qz66d1giYOH7vx62VAynB6e5fS4ZLMNsAfQ4UA4tUlE52zAbtF3G/UthL7rBAoqPnYi6OFAazWnb5UlqezqpC45iuzkMto3lV4A542B22Z0DQn/DLVxRyZGucqNFo97yIwq9HNuVMDU40FpROWatAr/fzgotVizBVI7rcWmA2fA//FsDgb3tzqjSMteZIuYdJz3koQ9fjJiGXJzwSdA2nNXmRJtwdY0hpCLV6BMR2sTMA== 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 Thu, Aug 29, 2024 at 06:56:07PM +0200, David Hildenbrand wrote: > Let's free up some more of the "unconditionally available on 64BIT" > space in order-1 folios by letting _folio_nr_pages overlay memcg_data in > the first tail page (second folio page). Consequently, we have the > optimization now whenever we have CONFIG_MEMCG, independent of 64BIT. > > We have to make sure that page->memcg on tail pages does not return > "surprises". page_memcg_check() already properly refuses PageTail(). > Let's do that earlier in print_page_owner_memcg() to avoid printing > wrong "Slab cache page" information. No other code should touch that > field on tail pages of compound pages. > > Reset the "_nr_pages" to 0 when splitting folios, or when freeing them > back to the buddy (to avoid false page->memcg_data "bad page" reports). > > Note that in __split_huge_page(), folio_nr_pages() would stop working > already as soon as we start messing with the subpages. > > Most kernel configs should have at least CONFIG_MEMCG enabled, even if > disabled at runtime. 64byte "struct memmap" is what we usually have > on 64BIT. > > While at it, rename "_folio_nr_pages" to "_nr_pages". > > Signed-off-by: David Hildenbrand Reviewed-by: Kirill A. Shutemov BTW, have anybody evaluated how much (if anything) do we gain we a separate _nr_pages field in struct folio comparing to calculating it based on the order in _flags_1? Mask+shift should be pretty cheap. -- Kiryl Shutsemau / Kirill A. Shutemov