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 7C06C30C147; Wed, 30 Sep 2026 09:32:40 +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=1790760761; cv=none; b=Kf9Zr2uNjv45FwLGm/pDi1s5K2fOqWiFNkJULWX0rtrHJR2A2ylYuyTTb6Y6CNrBQsxkHIzSVOLDvh1Wl1jHIMaDPkjhtJGP530xZog4U5RaDZ5MftPSguEzABYKK+nl4CKzV3ZyZm2VikY0kM9frmh5EZYnmgWPqK9zzcQien8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790760761; c=relaxed/simple; bh=TlzHEJQt+34xYjujqXxuq3JcjM0wYp8ZviYUagsVkog=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=garWEN3pTPZ7+NgDU1WHoJtjfajbeOywY3CMAhthbp1Wn6S/ZR7JDL1COPGG16xzzNMad5wxSVwPmmJwNRV0wutckgUP6s9N+LHPXG14nlYHw3+dWd5gAqMX8XpHnmCS89rzNhvWXYrh3iR4CfWqOLZv34HFKanSM5TiA59WRWk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A/WFPBAH; 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="A/WFPBAH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD21A1F000FF; Wed, 30 Sep 2026 09:32:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790760760; bh=GUhUebTYwdNTDsFDAgKX2XUga1p/xniYtUmuBOcAkD0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=A/WFPBAH7Qma+9hcX287RuSKWlORpntiWFjFLaPigU8Y75ISxg3KEjLTfteawEyBe 2g/cYh4OEqr71nkWwJpVQnorMprUQRkz1eix+QLOCr/CPst8lLD0ChCfFd8YGM4jfy Fksx04sLagSxxR88vp09QnJZCikrL8s15UEcYtyj8cHuNrsfav7blbRqRE5dyxX7SB IKNdTpYGGoAU9JjY6jjqMsEYQfRaLoK1HI3j102H2WUj2d2AjX7kJd1tm0yEuZtXim rxv3PmM3a58m4CHKDbt2tmNwqyH0M2+G0zuIAT/AqLpxmsAoL5566Xt1IaKFXihiLq k8Bhh/EDc3Mrg== Date: Wed, 30 Sep 2026 10:32:09 +0100 From: "Lorenzo Stoakes (ARM)" To: Zi Yan Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , David Hildenbrand , 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 , 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 34/40] mm: eliminate VMA_SPECIAL_FLAGS usage when hugetlb explicitly tested Message-ID: References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> <20260917-b4-mmap-prepare-vma-flag-sanify-v3-34-4583d8a23bca@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Sep 29, 2026 at 10:42:00PM -0400, Zi Yan wrote: > On Thu Sep 17, 2026 at 12:22 PM EDT, Lorenzo Stoakes (ARM) wrote: > > It is now an invariant that VMA_IO_BIT is not set except by kernel-owned > > mappings, so each existing VMA_SPECIAL_FLAGS test need only test for > > VMA_DONTEXPAND_BIT, VMA_PFNMAP_BIT and VMA_MIXEDMAP_BIT. > > > > This is precisely a test for a kernel-owned or fixed mapping. > > > > Update a number of callsites which already explicitly handle hugetlb > > mappings. > > > > vma_supports_mlock() and ksm_compatible() also explicitly bail on droppable > > mappings - detecting kernel-owned, fixed or droppable mappings is handled > > by vma_is_persistent(), so in these cases use this predicate. > > > > should_skip_vma() tests for locked, kernel-owned or fixed memory (having > > already excluded hugetlb mappings) so simply test for those there. > > > > No functional change intended. > > > > Signed-off-by: Lorenzo Stoakes (ARM) > > --- > > mm/internal.h | 4 +--- > > mm/ksm.c | 4 +--- > > mm/vmscan.c | 3 ++- > > 3 files changed, 4 insertions(+), 7 deletions(-) > > > > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index 12ed3388ee41..09ff20c3df5b 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -3477,7 +3477,8 @@ static int should_skip_vma(unsigned long start, unsigned long end, struct mm_wal > > if (!vma_has_recency(vma)) > > return true; > > > > - if (vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) > > + if (vma_test(vma, VMA_LOCKED_BIT) || vma_is_kernel_owned(vma) || > > At this point, mmap_lock is held, there is no mlock WIP, so > VMA_LOCKED_BIT is enough. Yes indeed :) > > > + vma_is_fixed_mapping(vma)) > > return true; > > > > if (vma == get_gate_vma(vma->vm_mm)) > > LGTM. > > Reviewed-by: Zi Yan Thanks! > > > -- > Best Regards, > Yan, Zi > -- Cheers, Lorenzo