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 C23E64BF949; Mon, 12 Oct 2026 18:07:17 +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=1791828439; cv=none; b=ouZFhgnoIxCv6J0i0liRPaRJGiVI7sBuTj9xSwfjaD2gS/XpuKRG7s4IUE0QBfcHDDdzFsrSN132ZBB+mZwR3M8ersOwUVwzHTelSlVh1Vel8ZbsMMtZNvncW9gTjarmTQpzzY5Tq1WkdBa8l+nY78iF4ubXRu1tRHvrbd56bew= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791828439; c=relaxed/simple; bh=UVXb20zARU7mExCFbWZKkVqMpDe490E7VM71fJSOZPw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=MTnt8XlWpHpx/vih72z6gPfw50UPZ0VWreMfsoN/5RoDM8/eRviZ6kr4Vx8UVBQa+Xn1nEswg0cuCf2pfqvtU2ozvZYqE2iIKAE9YD9/Vu0gJy8Y7v9LEMNpib+hKavttpwnJpZFx2JgsX1/VE2+7Z/tNulRkpfbRq1QZQZP3d8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Wt6owd8B; 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="Wt6owd8B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32BD51F0089B; Mon, 12 Oct 2026 18:06:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791828437; bh=DDDaNaIXKmjLMpGyOKitw9HvqeETc7OKRNfzQD54qxg=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=Wt6owd8Bq2u9/nEuC+sRUdT8+/OxfpX/2L+rcI0CI58dMdj5RepHEkZ+JK0a2NReh sfWZgwJnlIoxukhvfsVC549Mea8Lzn1FqlVFltYJjt8rHvk+/6/ZpWr6udcYD/Kvhv cYjJbTjIOah993HBTrzgv5z/AR+B5YNtKjygVS0MFHVStaBZhTHGGs3CePzg/YUyKR PxwC1y9KuoLdaWY3WCk7m3+ezYcwA/LnfPWK+S1wgKQ+eOE1YSCAXB3bijg6tQO5JH bHdtiENWAtXTXun/ecBlXYX2L4beb5ScOKLj6+Nr6PliXK0IY5395VSWd+QtTd+iS9 TJQjIG75WdKXQ== Message-ID: <7554094f-d853-482f-ba82-3e2f7b1cf4a0@kernel.org> Date: Mon, 12 Oct 2026 20:06:41 +0200 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 14/38] mm/vma: add vma[_flags]_is_mm_managed() predicates 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" , 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, Ihor Solodrai , Bert Karwatzki References: <20261009-b4-mmap-prepare-vma-flag-sanify-v5-0-923b70125b1e@kernel.org> <20261009-b4-mmap-prepare-vma-flag-sanify-v5-14-923b70125b1e@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 10/9/26 20:04, Lorenzo Stoakes (ARM) wrote: > Rather than referring to VMA flags with uncertain meaning, add a new > predicate that explicitly describes what absence of the VMA_PFNMAP_BIT and > VMA_MIXEDMAP_BIT flags means, and then refer to that function for > determining VMA mergeability. > > If neither of these flags are set, that means the contents of the mapping > are managed by core mm. > > Otherwise they are instead owned by some other kernel component, usually a > driver: the memory may be MMIO, kernel-allocated pages or even ordinary > pages the driver maps itself, but core mm must not populate, reclaim, > migrate, copy-on-write or merge the range itself. > > We initially also treat VMA_IO_BIT as implying a mapping is not mm-managed, > as by implication it cannot be. (mlock() also sets VMA_IO_BIT transiently > on ordinary VMAs while locking them, which is addressed later in this > series.) > > However the intent is to in future remove this, as no mapping should be > marked as an I/O mapping without also being marked with VMA_PFNMAP_BIT. > > This forms the basis of further work intended to improve how we express VMA > properties such as this. > > Also update the VMA userland tests to reflect the change. > > No functional change intended. > > Reviewed-by: Zi Yan > Reviewed-by: Suren Baghdasaryan > Signed-off-by: Lorenzo Stoakes (ARM) > --- > include/linux/mm.h | 53 ++++++++++++++++++++++++++++++++++++++++- > tools/testing/vma/include/dup.h | 29 +++++++++++++++++++++- > 2 files changed, 80 insertions(+), 2 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 97e1eb4fe3a4..83953757735a 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1612,6 +1612,41 @@ static inline bool vma_is_shared_maywrite(const struct vm_area_struct *vma) > return is_shared_maywrite(&vma->flags); > } > > +/** > + * vma_flags_is_mm_managed() - Do the specified VMA flags indicate that the > + * contents of the VMA are managed by core mm? > + * @flags: The VMA flags to test. > + * > + * Such a mapping is one established by a simple mmap() or brk() with no driver > + * or other kernel component involved. > + * > + * They are rmappable, and core mm services rmap operations including reclaim, > + * as well as population, CoW and merge/split (if eligible). I assume ->fault returning some kernel allocations (VM_DONTEXPAND set but none of the others) will currently contradict to that. But hopefully we'll clean that up in the future (or improve the documentation to cover them as well). Acked-by: David Hildenbrand (Arm) -- Cheers, David