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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 BCFACCA5FA7 for ; Tue, 29 Sep 2026 21:32:22 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4hvWbm6Ssxz2ySj; Wed, 30 Sep 2026 07:32:20 +1000 (AEST) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=172.234.252.31 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1790717540; cv=none; b=RKcQ2TuVbzw8BLR1FkrAsWVLTWw6Fq3xDtmyqMjWpa2odybc4qotTAbvY3qFGvzLOT8r4/DZ/Z+z5tCxfX/Ha2XKwHfEZl9AUfkHVLj/TWchmoQJ+lX1UoiB970cJQ6Ps6o/ihNtytMEoX9DhBgMOFu6pE3t1OnlkmaAECdSxPtxi8oGBbQ+ygCv/5loBPZKSpFLXZKkbF+rvqXHKeSdBVYv/8uU3Xo8UyjdMkpjej4oNwiG68PlWOvKuWDk/D6Pu/AYVjtBaiOTBKcKznbkFewBge6xNWVoqk2oNjqUjFgeV87c/yZ/tS+I5GgkH8hTVBH7nAWiZ4G2+GFKJnWLug== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1790717540; c=relaxed/relaxed; bh=bV1wlokKdVHLqPHNGwe/7vIopeMXy+gYUFpopQWEIt4=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=K45zh/GKYkleSh1Cb3q636STdDQVB2vN6mrRmDkjtywJBQPHqpIPCvDRhSFB82Fc7a5u4jM4npcC4c24zhF2ONJzZomnUEVwISoh9YgF66F0+j5I2EPqIxxMAvqmQ4+Ey+zoPXe+iNnlgfaUMgqFIK+FgPK3zIoJGiyRReldIu9/8+22xE4LYjW3uJRVNuDCx9qq8VNiGBb+tlP/cJlnMIn8NHKeVT4cmZdFCIw3qpPQszOey93Jy9IuY3Jn2barhiRbOmmUS/IEZz7DA0ioUMgXswXVYdI23nwZBLtJfdNe7uaDUMqISxvEw41zagKAC8V7lk1piz2h968AvTAKLA== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org; dkim=pass (1024-bit key; unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=D3vyCbxH; dkim-atps=neutral; spf=pass (client-ip=172.234.252.31; helo=sea.source.kernel.org; envelope-from=akpm@linux-foundation.org; receiver=lists.ozlabs.org) smtp.mailfrom=linux-foundation.org Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=D3vyCbxH; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux-foundation.org (client-ip=172.234.252.31; helo=sea.source.kernel.org; envelope-from=akpm@linux-foundation.org; receiver=lists.ozlabs.org) Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4hvWbl4sHpz2xnn for ; Wed, 30 Sep 2026 07:32:18 +1000 (AEST) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id B8DB043D33; Tue, 29 Sep 2026 21:32:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 068751F000FF; Tue, 29 Sep 2026 21:32:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1790717535; bh=bV1wlokKdVHLqPHNGwe/7vIopeMXy+gYUFpopQWEIt4=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=D3vyCbxHxJQ+aX1/mUxGlNGRXygGdhx3UDqmwRpHjeF9SrqNpUku1TQDoU18Eju+A Uvj+PN6PuV8lgvO1Uo60ys6S+sVxEDTN6T7mEYU3V9canHRrMkOUhO9Qkzk7wqeFeb v6vUPVcDn5zBCzMO6qK/hPO0ApMIFdNMFlbEMsgk= Date: Tue, 29 Sep 2026 14:32:14 -0700 From: Andrew Morton To: Muchun Song Cc: Madhavan Srinivasan , Mike Rapoport , David Hildenbrand , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Ritesh Harjani , Shrikanth Hegde , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Qi Zheng , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, muchun.song@linux.dev Subject: Re: [PATCH v3 0/6] mm: Unify device DAX and HugeTLB vmemmap population paths Message-Id: <20260929143214.9061bcf284369163192968d1@linux-foundation.org> In-Reply-To: <20260929053231.66085-1-songmuchun@bytedance.com> References: <20260929053231.66085-1-songmuchun@bytedance.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 29 Sep 2026 13:32:25 +0800 Muchun Song wrote: > This v3 is based on mm-new commit 2ddb90ee544a, which contains v5 of > "mm: Switch device DAX to section-based vmemmap optimization" [1]. > > This series is split out from the earlier, larger series "mm: Generalize > HVO for HugeTLB and device DAX" [2]. While the parent series generalizes > vmemmap optimization across HugeTLB and device DAX, this subset addresses > a single, self-contained step: unifying their vmemmap population paths. > > After the preceding Device DAX conversion, both HugeTLB and Device DAX > describe optimized vmemmap mappings through memory-section metadata and > use per-zone shared tail vmemmap pages. The generic code, however, still > carries a Device DAX-specific population flag and compound-page population > path, along with arguments and helpers needed only by that path. > > This series first removes VMEMMAP_POPULATE_DAX and moves selection and > reference handling for the shared tail page into the common vmemmap > population path. It then removes the generic Device DAX-specific > compound-page population path and routes section vmemmap population > through vmemmap_populate(). The powerpc radix path continues to use its > architecture-specific compound-page population implementation for > optimizable sections. > > The remaining patches remove the unused ptpfn argument, open-code > vmemmap_populate_address() now that no caller needs its returned PTE, and > add a warning for inconsistent zone initialization of shared tail vmemmap > pages. > > This is the fourth smaller step toward the broader HVO generalization. > After this series, HugeTLB and Device DAX use the same population model > instead of parallel generic paths, while powerpc keeps its > architecture-specific implementation. afaict the whole series is "no functional changes intended". Apart from [6/6]'s new WARN_ON. And [3/6] is the one which could cause unintended fuctional changes! Thanks. I'll queue it. Reluctantly. We're up to 688 MM patches this cycle and it's time to stop.