From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from flow-a6-smtp.messagingengine.com (flow-a6-smtp.messagingengine.com [103.168.172.141]) (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 6B7A2329C6D for ; Thu, 27 Aug 2026 14:58:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=103.168.172.141 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787842702; cv=none; b=jgTajMUXGWpftj0a4q0rA3AD+V8lt7Dc3yleiNo2hGl1Sy9q4ZqiaKLi7fJPES657ui8PnX/ux8Aet+gtJVS6kJBahNeLVLPiHMR7tIC2YWDX8ZHxBpi8kutZYqn/vOeVdnXzH+QvJ6pcxwDVNsmBuI5Sj5qsTYWrFyGmRsoeJU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787842702; c=relaxed/simple; bh=EQdUQDKTOMLx2miNRmh0eKRty6cnq2Y4C34CJPZAgTw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pBbBpcYLYPHi8ElhbPqymbFGf4HOL8/8zIP88UpO4ovcbgjH5/I3zmXzoTT5UVThxiBI8PU55PMdWM9hDZ7H5xwCUDbw3foOUfFBjHy1uIZ93MGctEP1DfAVx/tAtzwBcUPIKmfxiWczPCxy16sFBlTQHmwmq7/oiGtSRt3azYg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=shutemov.name; spf=pass smtp.mailfrom=shutemov.name; dkim=pass (2048-bit key) header.d=shutemov.name header.i=@shutemov.name header.b=kwRWFxPC; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=HRh8b7GR; arc=none smtp.client-ip=103.168.172.141 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=shutemov.name Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=shutemov.name Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=shutemov.name header.i=@shutemov.name header.b="kwRWFxPC"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="HRh8b7GR" Received: from phl-compute-02.internal (phl-compute-02.internal [10.202.2.42]) by mailflow.phl.internal (Postfix) with ESMTP id 7BF531380214; Thu, 27 Aug 2026 10:58:20 -0400 (EDT) Received: from phl-frontend-03 ([10.202.2.162]) by phl-compute-02.internal (MEProxy); Thu, 27 Aug 2026 10:58:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov.name; h=cc:cc:content-type:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:subject:subject:to:to; s=fm2; t=1787842700; x= 1787849900; bh=CZZ93FItI8JMFjwX7flkmn3kmtJ4ez+8sQ/nTIMgQBQ=; b=k wRWFxPChA/+9q+HXIqhe4ILwZV2YnpovrcH33nZrbiiMbQv1Fb+Vnsi/lA2l5bSA xGihqJFSM+OwSgMYJVfjxXYCrksDRFTu5rOsa0XTxp567gZ23vBrGn51zfXyTGTc LFBbkqCw0uaAQAkdY/KjMbfFBQqzNJw4IfOvhvWV+rPv5e+uWb7xOEURMNFWR3Ac MPn9RkUTT6q7Oim6HiVL5x08Edh6IFC/IKsi8H0SP/rlRkc+GhJ0vP9dOaN8fVGU MTz9FzosWpNr8iPWDVXbmhod78y68G/YIZXM5s2H8uKfZc83l0qruPm5fhiope58 OMRGp7Kdkkq2E2BQNreKw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:subject:subject:to :to:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; t= 1787842700; x=1787849900; bh=CZZ93FItI8JMFjwX7flkmn3kmtJ4ez+8sQ/ nTIMgQBQ=; b=HRh8b7GRH1oVgBmOfpccKrPL4lzHiPSwPGvF15i6Zk/kFma2Rj0 1KYJBxiBW1zwVpIKsjfKiQmFaYmTe4eCk5G6YxZYQDmZ1IWj/4aoD8V5sLRFw9VO V2J875dwPmZ9NB5qmpcFeQFd7WjvDCj+hyvIkNXJH9qCKA4LS3+jdCyiPc0yfmOt 9uxsNpe2sjsyR5BW031SMj8xs2PSZ9LHjJrOTiXfIFYZCJ8Nk1y+m20vdi5WYVjJ 8fArNzR5ibVBACypZmPUJBnEtLv5GyyJCSLdya1h5nCrmluvqaHw5D7Jg4q+2o2i L7zRfxvncrbbXu/b3Th2M+LipExr4E7lnNQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: dmFkZTE2YGGlRLn8o8CpHCnnIZ36wcEkXQe2Zjt8vFyB0bm/6DdRWdjZgbt61ucV3J13VS VBz7jEGs3zGW3cd925nfXGhllcdmwWbs8OS7LzZPwF9aCj7PiYtuU2lbI3gWb2EEkcuO36 iBb2WiHb0wSh/94oaiLLIOYIrhAHpNzqYHK5aAs02VkOKvVSNBLejFtl8+O0/TudfepxNA hla3yKqiRsIxTgZ9VU+t0AfjLb3BTnimv8pVLf6zyDT1EwCn540egbr7DcqcQ8wAzCLyCI S4wSXwx9Sr39euN967/gs3pN7QBLtYZMoBkD0zKPKKzvBx8Ue3bz9HZmsFLc31PX0PD0IX iI1A1/Y6oRDRCc1/W7I3g8DCnrfc5ZKjvCDzBoVr9yr8vHTChO/+chuA3eGn457/5B/JGi KJ8tXmHSiqEbDrMEY75S50FZ2uWuzu7mSQuEJhea7I4OJdFWQmuuGSQb574XLRvq0KkW6p MjBuX2Tq2UABEWaiZLUB/uXwHbxCCmTZprHWVdM5Bq3sRhp3ap6/hXM+VLfCf3KHH6jWVb 0ZL0yj+LgtaLv0I7aRd9DNn59Oi0Kag7HySLWszn4fNXbuxluVTZLb7E3d2ZXuRTZS6G9g tJOA3TYqfUhC9XalRHOJZpRgNpXEplDVeJla67NoyYSqftq1bKSWBfBHskvA X-ME-Proxy: Feedback-ID: ie3994620:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 27 Aug 2026 10:58:18 -0400 (EDT) Date: Thu, 27 Aug 2026 15:58:17 +0100 From: Kiryl Shutsemau To: kasong@tencent.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Chris Li , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Youngjun Park , Shivam Kalra , Kairui Song Subject: Re: [PATCH v3 04/18] mm/huge_memory: split the routine for splitting anon and file folio Message-ID: References: <20260821-swap-thp-cleanup-v3-0-9b43f5163238@tencent.com> <20260821-swap-thp-cleanup-v3-4-9b43f5163238@tencent.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260821-swap-thp-cleanup-v3-4-9b43f5163238@tencent.com> On Fri, Aug 21, 2026 at 02:55:17AM +0800, Kairui Song via B4 Relay wrote: > @@ -4064,7 +4095,6 @@ static int __folio_freeze_and_split_unmapped(struct folio *folio, unsigned int n > folio_put_refs(new_folio, nr_pages); > } > > - zone_device_private_split_cb(folio, NULL); > /* > * Unfreeze @folio only after all page cache entries, which > * used to point to it, have been updated with new folios. This gave me a pause. I don't know much about the zone device private thing and I had to dig to check if such folios are always anon. They are. But it is not obvious to me why this limitation could not be lifted tomorrow. Nothing in "not directly addressable by the CPU" implies anon-only. I would appreciate some explanation in the commit message and maybe VM_WARN_ON_ONCE_FOLIO(folio_is_device_private(folio), folio) in the file path to flag surprises. -- Kiryl Shutsemau / Kirill A. Shutemov