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 E76FACA5FDD for ; Fri, 2 Oct 2026 14:00:10 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4hx9Qd04qCz30B9; Sat, 03 Oct 2026 00:00:09 +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=1790949608; cv=none; b=bYXg7ooxd2yX43jgUC93XyHOqg6kr4UxyOFSA/GLif14giKVtbiy8TvKnKSkg7eAzei18DkgRbPTKfi2i9FXabWLDniaPUT5huDxl9DqFT8in9jHouowyPf/3cLLvwyBxeTDIYYblaOrz0i/PBd7AQ09NBj0PrxpdQ5FziPHP9WlK9nsOOPwFPu+CkpH90sqUj6ZXcnOXn827xNN49RL6d94vckLjvUv+9nHu/jUBuNAiEGvzrKEjqJdcaRAJNGsp1+W502cgprnc9nQ/rkoELjvlt3KkirksnoApowipaEoM6VAe5msvztXHe0MxiHIEjosVvYmj69wxJbnXny6hQ== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1790949608; c=relaxed/relaxed; bh=JrJqgz6XBqr0tqvrPwuWu3EbEV7kVO9oxqBplkAGfJ8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UQ+zsW9bVkkzzca3wHw7Tx5SY/1DmE5Mjwd+JENcmuU14140puydmLpT9b9gokHiCFOd1U/ySyaKiJ52GDlGUg9vxoz7thvbI6X249Tnrk4sd05AcnpfMJRBGmtcOsy1+iwjPQbxOZKXPTkfdbim6dCVxlf8OJ0Oa2ssfkDCESRCfw082tEHKoBjIMY43+7AxR+hYfRRy6/mA4wUqqsVJCQAT/mNHqplzE45XXtUvDD/lDDYDFZkcZBPhPMjmIztTp5p10yBG+x8enJDboZpH58TIvX1suK7U6jM+FwoAk/mKhu8Lc9PFAwC0bVn9FrRVMT45WyoShxqfSarWhqceQ== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lCWn9cDF; dkim-atps=neutral; spf=pass (client-ip=172.234.252.31; helo=sea.source.kernel.org; envelope-from=ljs@kernel.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.org Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lCWn9cDF; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=172.234.252.31; helo=sea.source.kernel.org; envelope-from=ljs@kernel.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) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4hx9Qb21XHz2xrC for ; Sat, 03 Oct 2026 00:00:07 +1000 (AEST) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id EDA1240F27; Fri, 2 Oct 2026 14:00:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 501EB1F000FF; Fri, 2 Oct 2026 13:59:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790949604; bh=JrJqgz6XBqr0tqvrPwuWu3EbEV7kVO9oxqBplkAGfJ8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=lCWn9cDFMJm4u1OpaqsPaifDSAYxVJq/u9IjTjW8VHaCqg4YN9JjvyLsXvAqt1QNy kXjsxEDBQVVSiIroM8JVx8jdbn5z+D3ALO2UR7Dt4oCwXbWLHzPI9wUTMqgwfU7Krj IZwSxYhHFuMLnMs6YBDMSwGCVs4RhT6DtJPo3InMpggMiPIDm38MOeNSzD7sXk23e2 RWLEF3oKpPBtzGR/mrLgeY6/R3hf0OeJ04oxiHGDqrqFlOeh7T6MsnVwgAIQ5juixO EyqksyZMc+ThciZZQxHOhRow8uXbh8X8CGyWqfIqAq62o4uBFfPnhBhtXmHvotijgD QT9fd+pxtot2w== Date: Fri, 2 Oct 2026 14:59:35 +0100 From: "Lorenzo Stoakes (ARM)" To: "David Hildenbrand (Arm)" Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Greg Kroah-Hartman , Dennis Dalessandro , Jason Gunthorpe , Leon Romanovsky , Paul Moore , Stephen Smalley , Jaroslav Kysela , Takashi Iwai , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Doug Gilbert , "James E.J. Bottomley" , "Martin K. Petersen" , Jaya Kumar , Simona Vetter , Helge Deller , Sebastian Reichel , John Hubbard , Peter Xu , Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Rik van Riel , Harry Yoo , Juri Lelli , Vincent Guittot , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Arnd Bergmann , Muchun Song , Oscar Salvador , "Matthew Wilcox (Oracle)" , Jan Kara , Marc Zyngier , Oliver Upton , Catalin Marinas , Madhavan Srinivasan , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , "David S. Miller" , Andreas Larsson , Alexander Viro , Christian Brauner , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Youngjun Park , Johannes Weiner , Qi Zheng , Shakeel Butt , Axel Rasmussen , Yuanchu Xie , Wei Xu , Chengming Zhou , Michal Hocko , Miklos Szeredi , Xu Xin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-usb@vger.kernel.org, linux-rdma@vger.kernel.org, selinux@vger.kernel.org, linux-sound@vger.kernel.org, bpf@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, fuse-devel@lists.linux.dev Subject: Re: [PATCH v3 31/40] mm/vma: introduce vma[_flags]_is_persistent() Message-ID: References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> <20260917-b4-mmap-prepare-vma-flag-sanify-v3-31-4583d8a23bca@kernel.org> <9bbdf4e8-6984-4477-a183-f0b236047381@kernel.org> <3557015d-23dd-41ef-9832-78b58587f3f4@kernel.org> <81e1e5ae-0aab-4584-81e6-3fc9c2634d07@kernel.org> <2e5a4e6c-8f9c-4050-8998-454b83f4823b@kernel.org> <3387642b-c39f-4f19-ba0c-267bbd2fe91d@kernel.org> 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-Disposition: inline In-Reply-To: <3387642b-c39f-4f19-ba0c-267bbd2fe91d@kernel.org> On Fri, Oct 02, 2026 at 03:11:27PM +0200, David Hildenbrand (Arm) wrote: > I'd be very happy if we could find a clear way to describe "this is what we call > user memory: anon+pagecache", if that could come handy in such a context. Rather than arguing about it, how about shifting things to 'what backs the mapping' and something like: /* big long kdoc... */ static inline bool vma_flags_is_mm_backed(const vma_flags_t *flags) { /* hugetlb is a fixed mapping, but the mm owns it entirely. */ if (vma_flags_is_hugetlb(flags)) return true; /* * Kernel-owned mappings are populated by their owner, and fixed mappings * have a layout the mm cannot assume ordinary fault semantics over. */ if (vma_flags_is_kernel_owned(flags) || vma_flags_is_fixed_mapping(flags)) return false; /* The mm has promised it may discard droppable memory at any time. */ return !vma_flags_test_single_mask(flags, VMA_DROPPABLE); } ? -- Cheers, Lorenzo