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 90554489FDD; Sat, 3 Oct 2026 17:56:53 +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=1791050215; cv=none; b=a54xYw01748Wz6BADyQF6ZxjcrCVJQ6c9P/FXOk9Ctv6VZhJzk9S8IC+9NZZrHDyzD+AtaYd1r9lPGti0tG1/y7nzCeeOXhSiG77oDZl4MsVBjMSWSdDQf4Ms5UIYXuPQITx+4w84ksJCG79/eRYaFVL8idFcrXo9py9NYqoZiM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791050215; c=relaxed/simple; bh=wUABm9EMjezdXKIokehHlzy+QEOSAsliDuXBFbXwkS8=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=gDzXRo0XgmHOzpWS5/Cx4x+uyw4l6nxDYkKPOLtE+i9sb4dUpIyXoECi4rfEpLNrqrPCoyS2yafrwdUpBES5IVDaiYDPIs8eKMcgjLPvK3nW3lyIBzD9zulYg55C2fIxZiNLcwAxyMhYlXBdGSuYL0vy5i7DLLer3UnzwvQNtuQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hjeeCpQ1; 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="hjeeCpQ1" 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 Reply-To: sashiko-reviews@lists.linux.dev 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> 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 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