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 B613154529E; Wed, 9 Sep 2026 12:08:59 +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=1788955741; cv=none; b=KLz8pHbYvCDCMZRab5KuwIwHeEyYsJlj0w00jBJgrQhWnAPpeKI6oOtrpGz4nxhPOGHV/pQgSe5xYnJc0+SoH+qyVuBwuMGtJV9EMqyc/2Y+2liB7VNXQ7mrMZ20RGpm+CyxDDQpH9DB5PSWVvqysKNNGgpYeB88zydbYPsZVTc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788955741; c=relaxed/simple; bh=Tr7NeP1XAHfJ7HqrKKBxhlWmTq0V2hBOX4MjlUrY6wo=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=sqMLKM8J5IWYEAJnG86qNukqnCpAebe15zIsiE9vuONNxw4cu1jUP4egA13BMjfD7Kn6QDx2DIgbfaGxr8TDbPfulDQVJii7NrDw6hr3qWn9kRSL21Gfv+nDhBNX0FPf+ZiPCKEnP/sCntgEminfaJaZDYDgBwvvObRFFw+kbZw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QSBO7XfB; 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="QSBO7XfB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EFC671F00A3E; Wed, 9 Sep 2026 12:08:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788955739; bh=+vl7JXesMvOyLvN4TqdpRFvW5tHWQV0Z6fTfMaOZcos=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=QSBO7XfB9eJuCgdZw4woX9h6hLVv1DAAKEMcqqTtIlfNGaiMpuLvQbzhC/HsUDqDy 15tzsyERcKb/dCy0KrTkU176RhbTCcy21TSs/XRVe0a2CeHrpUDlqlX+4eqWNdQmSP ZwfdXLWGjYgxyEXXB+UjA+lgDSAN24eS4K+Y/at+9+bmLKnF2sQtudlKc4XZf2yWBT GWiqoV+03Qgq8XKU5kEPlMdYwMF4DBOmSD8P6FFdNW88ziMwb+5x2tUJ7KBFC2OEkv y0F1ASE9ljvI2KQ6gM2g9pgM4YchyP5SgcvLLQZd8YcLUPlszfpfiqg7ho1AxZsTq8 3yCEIs6vu9sRQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1x4H6m-00000006flL-2cBD; Wed, 09 Sep 2026 12:08:56 +0000 Date: Wed, 09 Sep 2026 13:08:55 +0100 Message-ID: <86wlsu39uw.wl-maz@kernel.org> From: Marc Zyngier To: "Lorenzo Stoakes (ARM)" Cc: Andrew Morton , "Liam R. 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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 , Xu Xin , Chengming Zhou , Michal Hocko , Miklos Szeredi , 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 28/39] mm: drop some redundant checks around hugetlb VMAs In-Reply-To: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-28-dacf19cce22b@kernel.org> References: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org> <20260908-b4-mmap-prepare-vma-flag-sanify-v1-28-dacf19cce22b@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: selinux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; 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SAEximRunCond expanded to false On Tue, 08 Sep 2026 21:01:32 +0100, "Lorenzo Stoakes (ARM)" wrote: > > Adjust code which inadvertently perform redundant checks on hugetlb VMAs > and clean them up: > > * hugetlb VMAs have VMA_DONTEXPAND_BIT set so a VMA_SPECIAL_FLAGS check > suffices. (migrate_vma_setup() regains an explicit hugetlb test later in > the series, once VMA_SPECIAL_FLAGS is removed.) > > * hugetlb VMAs unconditionally set vma->vm_ops, so they are never > anonymous. > > * hugetlb VMAs do not set VMA_PFNMAP_BIT so checking for this is redundant. > > While we're here also drop a VM_BUG_ON() which the simplified check above > makes unreachable, and use the new VMA flag API. > > No functional change intended. > > Signed-off-by: Lorenzo Stoakes (ARM) > --- > arch/arm64/kvm/mmu.c | 4 +--- > drivers/gpu/drm/drm_gpusvm.c | 3 +-- > mm/migrate_device.c | 4 ++-- > 3 files changed, 4 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > index a7968f8d24bf..3c1240ffc38d 100644 > --- a/arch/arm64/kvm/mmu.c > +++ b/arch/arm64/kvm/mmu.c > @@ -1463,14 +1463,12 @@ static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva) > { > unsigned long pa; > > - if (vma_is_hugetlb(vma) && !(vma->vm_flags & VM_PFNMAP)) > + if (vma_is_hugetlb(vma)) > return huge_page_shift(hstate_vma(vma)); > > if (!(vma->vm_flags & VM_PFNMAP)) > return PAGE_SHIFT; > > - VM_BUG_ON(vma_is_hugetlb(vma)); > - > pa = (vma->vm_pgoff << PAGE_SHIFT) + (hva - vma->vm_start); > > #ifndef __PAGETABLE_PMD_FOLDED Acked-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible.