From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B089D181334; Fri, 2 Oct 2026 07:07:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790924826; cv=none; b=VHCYvs3w0BzFMJBjUWuYkfGTUnaLuUdVjr5rFMJfKhuMd0Srm8i8zuI+pav3Opk3vo9ydoulPMVIUSjh+erTPfMwl3XugpyyatvDryh3uVD2CylNW842YpPbO625lVTXPxMCQqh/2jMAsJ3AJ38sf11XBe+mswkueGnVhH+cLEs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790924826; c=relaxed/simple; bh=CbNIWfwNrr5r64TP4bbtir4KpMfuf66zENudqWXyGaY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=S2Lltt0ZiR7e+HMmc0xDXXweuIHuWQkFZ/HJZip0nXKZo93UFX9WmLrCIEf/icoHjYWOZG9t2T2VNVbGObpNaRDNOQ5Jt6rG2pgGFLP6LYX8MzP+CA7BPb2OL1H5W8g+WDaV/ShWpKkUaJvcFkKvDPJ8Ro/fXC0JkFQEdDTWDLk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hCp+2fkS; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hCp+2fkS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5F6261F000FF; Fri, 2 Oct 2026 07:06:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790924825; bh=w0hWcnJnpydfH/GKmmOH7T4iJhQmbefzXV8L2WDslX0=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=hCp+2fkS7OxRcZij2y6mBt2E3fDjEzOc8eHQJhsPx6m3He/HdHGtPW8k/6BALSnES it9LIVVbOqRgF48rSD4m4wkZr4hRQPc326H3ja1QY80lqE6iDoDqoZY08TD6Vm4Yes 4JPqjTXiinMSYZN9WiIVnXy9fwCU+AhW+ZvjF+G+XIeE3rg8a8zPNSdbxV/F/NnBVe yHFUXl/91pMJM4tYtl2NVWacIZgiVwfPtWjYJeDkPfVagJjZ/YB8wc2ATnaZvC5PST VLDbqudcowc61gUKiq9yWqil67iFcoNVjQuPuSzPeWpzp8TUN4jjZAsuXZKXY9oCTW 54TzUxJRCkj8A== Message-ID: Date: Fri, 2 Oct 2026 09:06:22 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 35/40] mm: eliminate VMA_SPECIAL_FLAGS check in lru_gen_look_around() To: "Lorenzo Stoakes (ARM)" , 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 Cc: 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 References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> <20260917-b4-mmap-prepare-vma-flag-sanify-v3-35-4583d8a23bca@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/17/26 18:22, Lorenzo Stoakes (ARM) wrote: > A kernel-owned or fixed mapping is one which sets VMA_PFNMAP_BIT, > VMA_MIXEDMAP_BIT or VMA_DONTEXPAND_BIT, which is precisely what > VMA_SPECIAL_FLAGS tests for other than VMA_IO_BIT, which is safe to drop as > only kernel-owned mappings may set it. > > Using these predicates rather than VMA_SPECIAL_FLAGS makes the check > self-documenting and helps eliminate the confusion around 'special' flags. > > No functional change intended. > > Signed-off-by: Lorenzo Stoakes (ARM) > --- > mm/vmscan.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 09ff20c3df5b..001f8b760266 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -4418,8 +4418,8 @@ bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw, unsigned int nr) > if (spin_is_contended(pvmw->ptl)) > return true; > > - /* exclude special VMAs containing anon pages from COW */ > - if (vma->vm_flags & VM_SPECIAL) > + /* exclude kernel-owned and fixed VMAs containing anon pages from COW */ > + if (vma_is_kernel_owned(vma) || vma_is_fixed_mapping(vma)) > return true; Acked-by: David Hildenbrand (Arm) -- Cheers, David