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 938344D17B7; Thu, 17 Sep 2026 17:27:02 +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=1789666023; cv=none; b=tWb2GFeRSSGd6N2kY4FGiN1NZSmmeZpUgJGz/n0Tdke+BwPUvQN4wNfIUBOkN2iP73Aw7QSd0nhvwRIgBYCtlyYTZclizzD9Te1dPa8XdB2JkMiTM+8q6KRGSVW6AwvhEmB+e3qVTEbh/6/T+JUe/W7JsueWtRL1Uz3vdeOOajc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789666023; c=relaxed/simple; bh=v3UhQiz8AmAPpRrxRLbtp7TQEavk8vTuQrUPBhxh86M=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=K025cbtP3OKZUJWFzeljdL3mitOp8PUt20DUfVVXyMw2mI53+E3LnQER3vikWtI6e8ptv3Yu7RGKZfiJRlQGYhdxiEO0laaPDHnAlOGvwijXfZJXAle3PpnjTc8ugBWVwPDANkG9SjcWlvBlX9wuiJaA0HSoM1X2gJ8wFjjVCsw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bvKvmVZr; 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="bvKvmVZr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C78B31F00898; Thu, 17 Sep 2026 17:27:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789666022; bh=v3UhQiz8AmAPpRrxRLbtp7TQEavk8vTuQrUPBhxh86M=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=bvKvmVZr6yKb9k5x8WN66FBb5S4j9VAooeVfDl3ium8lWLtKGMhw+8W92VuniDYkA EOGA9v4lMsJ4u2IRcWIvzO0lGGIRrUSrdM28KEkz36OUMx1urslP2weE4JoDVXaL4z RKw4JcsWqOQ2DJU5hvvV72RSGArPv+G2Sg4+KlcUZRxsAJhhdt4cOxfYGvtdWM8/zZ j9IshvQyo43Syy0iuYNu+4Wk/RbgPiqidot1s4XrcMXOdUmzhyvyRJiv0rFtC3HTg3 Bek9TVk3R4xXhf5uS+F9sBwuh9m3i93nFew4invO7M6hIUsPpkUBF6fmur9wAUAgEj H53ndwe8a4dHg== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 17/40] mm/vma: add and use vma_[flags]_is_fixed_mapping Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: kvmarm@lists.linux.dev, "Marc Zyngier" , "Alexander Gordeev" , kvm@vger.kernel.org, bpf@vger.kernel.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, "Heiko Carstens" , dri-devel@lists.freedesktop.org, linux-perf-users@vger.kernel.org, linux-rdma@vger.kernel.org, linux-trace-kernel@vger.kernel.org, "Vasily Gorbik" , "Christian Borntraeger" , selinux@vger.kernel.org, "Oliver Upton" In-Reply-To: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-17-4583d8a23bca@kernel.org> References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> <20260917-b4-mmap-prepare-vma-flag-sanify-v3-17-4583d8a23bca@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 17 Sep 2026 17:27:01 +0000 Message-Id: <20260917172701.C78B31F00898@smtp.kernel.org> Precedence: bulk X-Mailing-List: kvm@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 > Also update the userland VMA tests to reflect the change. >=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/20260917-b4-mmap-pr= epare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org?part=3D17