From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 99D7631E107 for ; Thu, 26 Mar 2026 09:23:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774517009; cv=none; b=AJZfIx4Rs/CYdOoB2UcQGU2Lk/WbYcoUCZDsqMXnH/erDCgdd5UPUbrTlY6z7ueMkHQOVOLh5b8AenO7SzHBXy8m+H5XbB4aAEdfXRl3wEDMgGyWNg1a7y+m4yQq8OoJ+yE4cTU/EYZXdweoM1xx82+a8851Q2a9BjY8mrpNpRs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774517009; c=relaxed/simple; bh=vvvfL4L6rjlE4p3zlY+c8eev/dMIiWoJ6w71OFXwFGk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=VGwLVTgSZIn1gtANlDvWVPbeR1hsrPOAzv2QRG81rFJw4vytBYFgTiGUyJRvuvYMokIMR418Mk3Oyn+zhyhgxF+xJKQDqlUps1vZGXoWXeZI9vX8VSw0YeTQgVTaPzPFwUczstVzNYkPWsd+fSA5PChN6Oh+HBVmYWwfIL80zB4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nW0qDXZp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nW0qDXZp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C69BBC116C6; Thu, 26 Mar 2026 09:23:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774517009; bh=vvvfL4L6rjlE4p3zlY+c8eev/dMIiWoJ6w71OFXwFGk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=nW0qDXZpWFsRESTdbhVpOHnzCh3o4J/g0ytAiC6lbT1blHcUPtvWGoBRUDb6XkuCY T+swgSx/JBp6jI3aMPHv2wCbaYawMTUufhFN2/nT8niJR8x3FoKHbiLRoH4XqSeQCG jxKf7CZEJunmrpqWAIkrdpOGrUWKtOOMP2py+hSShK1qjfpL6bjhv8L1HO00Rovrdt 7wiR1fesnxgdXuhUSOXrg/+AhElA+8pdwErkWjJNCIfH0jRf4g/K3wvXEFe1X3m6VY y6B2g8XcpLBMQDqWCY0FVZ3sTMYfqyNlloFYBesEzNtkIctSf+hvApS7nvOPwYowbd gIKQufLbYm4oQ== Message-ID: Date: Thu, 26 Mar 2026 10:23:21 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/memory hotplug/unplug: Optimize zone contiguous check when changing pfn range To: "Liu, Yuan1" , Oscar Salvador , Mike Rapoport , Wei Yang Cc: "linux-mm@kvack.org" , "Hu, Yong" , "Zou, Nanhai" , Tim Chen , "Zhuo, Qiuxu" , "Chen, Yu C" , "Deng, Pan" , "Li, Tianyou" , Chen Zhang , "linux-kernel@vger.kernel.org" References: <20260319095622.1130380-1-yuan1.liu@intel.com> <48b497e5-1545-4376-a898-f3813a6ef989@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit > About AI feedback below > > init_unavailable_range() uses for_each_valid_pfn() and skips unmapped > sections that lack a mem_map. If the full hole size is added anyway, > pages_with_online_memmap could artificially match spanned_pages for > zones with missing sections. > > Could this make zone_is_contiguous() incorrectly return true, bypassing > pfn_valid() checks and potentially dereferencing missing sections? > unsinged long zone_hole_pages > > I think if I can update the pages_with_online_memmap in the > init_unavailable_range directly. See how I handled it: I simply return the number of initialized pages from the function. I think that should do. -- Cheers, David