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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 546A1E63F1E for ; Sun, 15 Feb 2026 23:14:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CUvQUhNOaSlrwhnJa0anCEJt56zA3FtYFY0sj8w0uRI=; b=cniwKrf4OtUysr hXitKDPY+MHyVI/CcHxt76wslzDrPvePD2b+BrOujK/udVz5daVy8p/HFB/E+lHoXWvOv256n4UR1 HVEdN1EpXT6A9YHvuLIjvM/G2St2xdWJkazGHa69cCXCNspHGq1CqprXM+8jhANF7t7pjZ+DDat2m fmX2K+WjMowN8HCOZpL0xW0Po5MY2rzrW4So8rM7UW/Tjk6GJIvHBolx/C589frjqU+nVJ77V/Hvw tUrQJswufnCKuPEFuIVyyljDGJk4N0N+QAeuUNDbVR77mr1x1eVgbDmyyDhMYrVyPG6EvKIcEdJIZ 9YaZ/47I5830Z5f39QNA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vrlJQ-00000005l5S-0Hkm; Sun, 15 Feb 2026 23:14:00 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vrlJO-00000005l5K-3jth for linux-riscv@bombadil.infradead.org; Sun, 15 Feb 2026 23:13:58 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Orx67w0OdZsiD/sxqMgXoLutvDapJy44psufStBNd34=; b=Tq38ZBkwHinLdgKHuJ2F6wb0Lw nuKJ0utimPTEs5necEg4OiOp93omwKGRX71185wTqzVACW8X/Btm5RQFtI2l9t/0LXp/dZlyaIOLM GehWSFz/SBsnkXJyZynrq8iJyDwnyPiZ75nYhPdeisBx/mBVpuALLKyyepWJzVzLGdsoKKXUpVTrP UiG1h5BkIqArcpktGdrJGEQfcuC7wHIfdw2rR8FSTBse3ekOr3x0SqqKT2TOwpGA16cFQh9WQ4mcJ 1LELudn4ti3SdkfASP4GSMU16UMLBkxEsG2Ob5cpm0F+uWJ/zPQ4zd/VuW57a7wmiDUp7TXRaurH9 jJ6U3oAw==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vrlJH-00000001duk-2IlM; Sun, 15 Feb 2026 23:13:51 +0000 Date: Sun, 15 Feb 2026 23:13:51 +0000 From: Matthew Wilcox To: Kiryl Shutsemau Cc: Andrew Morton , Muchun Song , David Hildenbrand , Usama Arif , Frank van der Linden , Oscar Salvador , Mike Rapoport , Vlastimil Babka , Lorenzo Stoakes , Zi Yan , Baoquan He , Michal Hocko , Johannes Weiner , Jonathan Corbet , Huacai Chen , WANG Xuerui , Palmer Dabbelt , Paul Walmsley , Albert Ou , Alexandre Ghiti , kernel-team@meta.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org Subject: Re: [PATCHv6 08/17] mm: Make page_zonenum() use head page Message-ID: References: <20260202155634.650837-1-kas@kernel.org> <20260202155634.650837-9-kas@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20260202155634.650837-9-kas@kernel.org> X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Mon, Feb 02, 2026 at 03:56:24PM +0000, Kiryl Shutsemau wrote: > With the upcoming changes to HVO, a single page of tail struct pages > will be shared across all huge pages of the same order on a node. Since > huge pages on the same node may belong to different zones, the zone > information stored in shared tail page flags would be incorrect. > > Always fetch zone information from the head page, which has unique and > correct zone flags for each compound page. You're right that different pages in the same folio can have different zone number. But does it matter ... or to put it another way, why is returning the zone number of the head page the correct way to resolve this? Arguably, the caller is asking for the zone number of _this page_, and does not care about the zone number of the head page. It would be good to have a short discussion of this in the commit message (but probably not worth putting this in a comment). _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv