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 9B0F851AFDA; Fri, 9 Oct 2026 18:29:58 +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=1791570607; cv=none; b=fySH11pyGd8Fv1Tzur2OlygtQp9LI1oh7V4KLXoJ676nTI1m6650gITiUo18nNBG8AB+JDQt4R/SKj/TnjxM02j4cnlWB84PcTWZVxL9B3TwK05pBjBrYBr9F9bfXy/AU609jYys8q0iClQHlL4jWJZSIfNm/g69VzeshYm1Be8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791570607; c=relaxed/simple; bh=D135us/EzyIcaFiwVjMoComriRxqTzNReNuNS5rfgmY=; h=Message-ID:From:Subject:To:Cc:In-Reply-To:References:Content-Type: Date; b=MHjdWrz7c42r1uWmSKFYPg4bEpC7R/4eR9UhaEsazkvwQ9Dv5Xd2pn5d1ypKC2HOzQJg1+4SQ+nmyCSbD1hMvNSJFIO8PGJMJsT8xzA5Rat/hv7OSUXqyeOhO2rX5l5PzwFvWyUdN6mshMCZ3B+juSv3dRCSA32wUEqLxG722wU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LyzhLYXo; 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="LyzhLYXo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BE4B1F000FF; Fri, 9 Oct 2026 18:29:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791570598; bh=D135us/EzyIcaFiwVjMoComriRxqTzNReNuNS5rfgmY=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=LyzhLYXo//22UoCiTK0Rx7zMu5p/Vm4aqjtiG8e5cvo2dRKAI3XUEvsXmreGBXAh7 XD4JS7duc32FTn4bL7Hck5+iWkkPsCKwW0ckrX2xLeYyxGVkKcp3BZMa+tR8An+FXn W7E+YBQaXpeLhh2JObz7f2Hla1Gikux+m/Pp/tM70JJXGlnzdQybboUV553kYNdsAM YTB14fP4Pa58oQ+Rp5Z6jNre3rhJ9GknimSNUMnKeYYGYyNPIUxseoH1OjwKCinF34 ltRaVKIj7jBUVNu0LLLVG+T8QWW2Q+j46Ke+oTnvC3gTapyh7BTF4WpizOZ+/45VZ7 A4OnXSVidOSGA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v5 16/38] mm/vma: add and use vma_[flags]_is_fixed_mapping Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: linux-trace-kernel@vger.kernel.org, kvmarm@lists.linux.dev, "Vasily Gorbik" , "Oliver Upton" , "Heiko Carstens" , linux-perf-users@vger.kernel.org, "Marc Zyngier" , "Alexander Gordeev" , linux-scsi@vger.kernel.org, selinux@vger.kernel.org, "Christian Borntraeger" , bpf@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-usb@vger.kernel.org In-Reply-To: <20261009-b4-mmap-prepare-vma-flag-sanify-v5-16-923b70125b1e@kernel.org> References: <20261009-b4-mmap-prepare-vma-flag-sanify-v5-0-923b70125b1e@kernel.org> <20261009-b4-mmap-prepare-vma-flag-sanify-v5-16-923b70125b1e@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 09 Oct 2026 18:29:56 +0000 Precedence: bulk X-Mailing-List: bpf@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 mappings not managed by core mm, 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 > Reviewed-by: Zi Yan > Reviewed-by: Suren Baghdasaryan > 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/20261009-b4-mmap-pr= epare-vma-flag-sanify-v5-0-923b70125b1e@kernel.org?part=3D16