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 41A593B058A; Tue, 8 Sep 2026 20:42:12 +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=1788900133; cv=none; b=sz5PpgSyFJkbB4Sqnfzmcwrz/o48mlmgYhxkZICmB5ad44/34+7v3YZZ7h7sDxCFtuxjCNFzr4zT/3rHM+5DalUfwxh7lU/DfO0KH1h0Yct+yDO96bbRuvZtXIDgR+E/h8N/OR92ngwjOdN8UVuHoihwcFgt8xdiQCgUvRVvRFM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788900133; c=relaxed/simple; bh=ZEHXXIn5MPhqvEFo2IZk3OAkWv+n7ylTTyz8NGZ5HlU=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=sFU/GYIjQt+O6IVqiFrWALgFVt+dJ6yOFNfavFeOFwvcbb2C5npk8IiWySTt/16SvrRcHaPKUZ1WzBUrFH7xOpmAuOpZESlX8qI2OXFYi78UCAdTffdqxaCHn9MniPaTJGODpWYhkt49EQz4QNx8T3pQ/mswhM4OZYyt1jL/T+0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QVENvXy+; 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="QVENvXy+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 505551F00A3A; Tue, 8 Sep 2026 20:42:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788900132; bh=ZEHXXIn5MPhqvEFo2IZk3OAkWv+n7ylTTyz8NGZ5HlU=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=QVENvXy+w5E29pNkrXUvhpfma0eJ3SaQ+KREk1R4WPFe8FJyVnPghIwnav7AmxPqD wUhW5K87e3jZF3kZqKuniPKHYddBRKFrMN2jMBtZKlNzqMqf/6FSiuh4nT2VidtUH4 eKfio2fk1wETy+nlvz4MHr554/3hCaJDC6OmhkA11SInoZn9rIEv7DQjYg9A6Hsqlz 1Q+PaAYqGDODlaYIRoC60PDkfBU3n0Re063FmUkWfyyXxKc83gvQbbYmZMNnlAa+dy nAFjKqOneyTB7FQ8pIIBEF7tiohdLxYaC+o+UXzajRaRTEy5EcUYZr8LdV60h4ZyHB 1UKEYG6OL4ayg== From: sashiko-bot@kernel.org Subject: Re: [PATCH 16/39] mm/vma: add and use vma_[flags]_is_fixed_mapping Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: "Marc Zyngier" , "Christian Borntraeger" , "Alexander Gordeev" , linux-s390@vger.kernel.org, "Heiko Carstens" , kvm@vger.kernel.org, linux-trace-kernel@vger.kernel.org, "Oliver Upton" , kvmarm@lists.linux.dev, linux-scsi@vger.kernel.org, bpf@vger.kernel.org, "Vasily Gorbik" , linux-perf-users@vger.kernel.org, selinux@vger.kernel.org, dri-devel@lists.freedesktop.org In-Reply-To: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-16-dacf19cce22b@kernel.org> References: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org> <20260908-b4-mmap-prepare-vma-flag-sanify-v1-16-dacf19cce22b@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 08 Sep 2026 20:42:10 +0000 Message-Id: <20260908204211.505551F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: selinux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > This determines whether a VMA cannot be expanded or merged because what > they mapped was determined to be a set size at mmap time. >=20 > This typically refers to kernel-owned mappings, however VMA_DONTEXPAND_BIT > is not reliably set alongside VMA_PFNMAP_BIT or VMA_MIXEDMAP_BIT, so we > must explicitly test for this for now. >=20 > We also explicitly test for VMA_PFNMAP_BIT as VMA_DONTEXPAND_BIT may not = be > set for VMA_PFNMAP_BIT's despite the one implying the other. >=20 > Use this predicate in vma_flags_can_merge() and in check_prep_vma() in the > mremap logic testing to see if mremap() can expand the VMA. The criteria > for khugepaged and MADV_COLLAPSE eligibility in > __thp_vma_allowable_orders() are precisely those for mergeability, so use > vma_can_merge() there (with an expanded comment). >=20 > This obviates the need for the VM_NO_KHUGEPAGED mask, so remove it. >=20 > Hugetlb VMAs remain excluded from khugepaged as hugetlbfs always sets > VMA_DONTEXPAND_BIT. >=20 > No functional change intended. >=20 > Signed-off-by: Lorenzo Stoakes (ARM) Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260908-b4-mmap-pr= epare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org?part=3D16