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 76F4B485952 for ; Fri, 18 Sep 2026 12:15:46 +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=1789733747; cv=none; b=b2zprOul3QSzKzPOX2RzuJruJJjPLvVvG1W4mWCPpwTHH1KUA93hYmB0JdDp6XVWUHKpe9vNrxpwxH6APsdNQwIgB4ZyNh84VoI/lt6z7ochMrHVKBlfzIpyBh+RLOPYXa/4Kib6ORC8IkgrbU3bfqIYAjZn7DphNNvm2rJB5Oo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789733747; c=relaxed/simple; bh=W1tv8dE3DY7Bm6UGQ2cDOk2nBGv7N8eN8buQAF5nRG8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Ia4ANxb/XFADlwQxWU7JULR7FtltGw4dXieIwJG98fPEJgm2hQQJEFzPWInUSrXBP6m116JyazLfkEXdEKeDjztSazBioaZHMlLnpAB478yhrtuTxllAV7GKsF2vHtRtiG0aVVK21D8MDdyCw6lrbttBe+v/3R8o6fhysMqAjSA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=b0tjc5YK; 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="b0tjc5YK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9BA3B1F000FF; Fri, 18 Sep 2026 12:15:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789733746; bh=NrjzlvBlcAthqMoY0nUVtb7DfpEhHoAJ1WT5vLNBdqU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=b0tjc5YKb5z/mOo26YG2o/5X179Uj+KYWyXsu3iTwmy38EFVW2xTdSCsY7VFz25sX uDnKdJK2P0j0TlQ3ByPsfIIbcoezS/dPVZRNWXmv7Q40EnGOPHtmPtYI3Gqr1sZ3Ma IwPuxefaqX+K9SJlDlz39mpeJ9sC3Z1PJvdBRxjG1j2lG6eIo8DRUBWB2twm3Uql8K EmWrKZOPRO4/0hikl3b3vn3ZeOuA1RFeug4pnSZs6wOe9/aP5m5nSLKSAEyqJZhkRc WHABB+17IQX5TjGX+SWBYc4B6UcJJJmYV7xeBHn8IJx0gvrGHtJOzUp9K03xVGyksr vX9+IXrQ4tIIA== Message-ID: <37e9fc88-4896-482f-bc6b-9023d4419783@kernel.org> Date: Fri, 18 Sep 2026 14:15:39 +0200 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 v9 2/2] mm/memory_hotplug: optimize zone contiguous check when changing pfn range To: "Liu, Yuan1" , Mike Rapoport Cc: Oscar Salvador , Wei Yang , "linux-mm@kvack.org" , "Zou, Nanhai" , Chen Zhang , "Zeng, Jason" , "Chen, Yu C" , "Deng, Pan" , "Li, Tianyou" , "linux-kernel@vger.kernel.org" References: <20260914072929.1883794-1-yuan1.liu@intel.com> <20260914072929.1883794-3-yuan1.liu@intel.com> <209de483-a9a5-4d98-bda4-7998e8fdc7da@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 On 9/18/26 04:08, Liu, Yuan1 wrote: >> -----Original Message----- >> From: Mike Rapoport >> Sent: Wednesday, September 16, 2026 2:58 AM >> To: David Hildenbrand (Arm) >> Cc: Liu, Yuan1 ; Oscar Salvador ; >> Wei Yang ; linux-mm@kvack.org; Zou, Nanhai >> ; Chen Zhang ; Zeng, Jason >> ; Chen, Yu C ; Deng, Pan >> ; Li, Tianyou ; linux- >> kernel@vger.kernel.org >> Subject: Re: [PATCH v9 2/2] mm/memory_hotplug: optimize zone contiguous >> check when changing pfn range >> >> On Tue, Sep 15, 2026 at 05:20:07PM +0200, David Hildenbrand (Arm) wrote: >> a >> pageblock >> cost >> pfn, int nid) >> last >> spfn, >> section >> However, only >> online. >>> >>> >>> Maybe extending that a bit we could do >>> >>> "With CONFIG_SPARSEMEM_VMEMMAP, early sections have a valid memmap for >> all PFNs >>> and the sections are marked online. However, we might have offline >> subsections >>> in such early sections, indicated by the subsection map. While we must >>> initialize the entire valid memmap, account only the online pages >> according to >>> the subsection map as online (see pfn_to_online_page())." >> >> init_unavailable_range() already has large comment on top, adding >> something >> like that there makes perfect sense to me :) >> >> How about a bit different version: >> >> * The function counts pages that should be added to >> * zone->pages_with_online_memmap. >> * With CONFIG_SPARSEMEM_VMEMMAP there could be offline subsections even >> though >> * the entire memory map is valid and all the early sections are online. >> * Count only pages in online subsections (see pfn_to_online_page()). > > Hi David > > Should I prepare and send a new version based on Mike's latest suggested changes? Yes please. I guess this comment is the final bit before this should be good to go. -- Cheers, David