From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 64E80CA5FE6 for ; Sat, 3 Oct 2026 17:56:56 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C095510E980; Sat, 3 Oct 2026 17:56:55 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="hjeeCpQ1"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4310010E984 for ; Sat, 3 Oct 2026 17:56:54 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id BDA4960DA2; Sat, 3 Oct 2026 17:56:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A203B1F0089B; Sat, 3 Oct 2026 17:56:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791050213; bh=wUABm9EMjezdXKIokehHlzy+QEOSAsliDuXBFbXwkS8=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=hjeeCpQ1UlXlFAiYuA2C/sR4hoTmn30Mm8Emn8IQ0eSCvO7b52NN67wXUA6fcLDOG fROTRLYg0mb4lpoXWMddY0Aj+Uqb4Le0Nt5zYp/wrRM2oOHY3yZ/fq3IV5ijcfbXdG FvgBir88NLMQj/YjN04w7GZGzQZAlg75hm49yh8lFRRDn4F6lM0+3KreUxbk6Qe/rO tVdtvXM62F74U5ov/hPwvFKK9Dyj3mfiP3y+XUAbLChTLzVIh4TYNm0F4HAU8Rpk1w CwErgvNfLzc9xYJ+Pi9zp4QW8H0dQHW9jqjBUHCW+6s6d4Nfy7R/80DOgDwRFNjdFa 76LJ0toexCG5A== From: sashiko-bot@kernel.org Subject: Re: [PATCH v4 16/38] mm/vma: add and use vma_[flags]_is_fixed_mapping To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: dri-devel@lists.freedesktop.org, "Heiko Carstens" , "Marc Zyngier" , "Alexander Gordeev" , linux-rdma@vger.kernel.org, selinux@vger.kernel.org, "Oliver Upton" , linux-scsi@vger.kernel.org, linux-trace-kernel@vger.kernel.org, "Christian Borntraeger" , kvm@vger.kernel.org, bpf@vger.kernel.org, linux-s390@vger.kernel.org, linux-perf-users@vger.kernel.org, kvmarm@lists.linux.dev, "Vasily Gorbik" In-Reply-To: <20261003-b4-mmap-prepare-vma-flag-sanify-v4-16-a1f052500fd7@kernel.org> References: <20261003-b4-mmap-prepare-vma-flag-sanify-v4-0-a1f052500fd7@kernel.org> <20261003-b4-mmap-prepare-vma-flag-sanify-v4-16-a1f052500fd7@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 03 Oct 2026 17:56:52 +0000 Message-Id: <20261003175652.A203B1F0089B@smtp.kernel.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" > 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 > 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/20261003-b4-mmap-pr= epare-vma-flag-sanify-v4-0-a1f052500fd7@kernel.org?part=3D16