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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C6C16CCF9E3 for ; Tue, 4 Nov 2025 12:24:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 104338E0135; Tue, 4 Nov 2025 07:24:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0B4B38E0124; Tue, 4 Nov 2025 07:24:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EE5D38E0135; Tue, 4 Nov 2025 07:23:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id DAFCE8E0124 for ; Tue, 4 Nov 2025 07:23:59 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 7224B140531 for ; Tue, 4 Nov 2025 12:23:59 +0000 (UTC) X-FDA: 84072841398.03.AF46EA9 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf03.hostedemail.com (Postfix) with ESMTP id ADAAA2000B for ; Tue, 4 Nov 2025 12:23:57 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=K9Fi45Ya; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf03.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762259037; a=rsa-sha256; cv=none; b=XeZXFiupCz8w9Cqxf/oCyJSJdMap4ZMkWZBd2Ld7ww6N7dQGIZF2c6TvhZpv/gxCIWKOi0 UdOc1+JW1tlgdOiIu/Dbt6yvHQt6qJcY7LysshcSYXwvkfWMpcHC8lEY9LXIJ1vRc19jDT 1IGDJuiBYPrOi2AylErmTL/Jyuq51vU= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=K9Fi45Ya; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf03.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762259037; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=V6P3uoQL4uWs+t5G+p0taETLOYUGgok1YeVz+E2jRpg=; b=pZQXUB/HuS+cahGjJd/hABSabcWX8O1QFort8mkzIhvMo1MaG4MrzvupIGiO9u+BscGEvA eMRaNC0qwyq1bcGxEL+zJxTKizSTbwT5mnG/3qk1OdCJBzIzxrGjX619djygKIn6jjgeWp 7LVDkpMrxLejH+ZnW/xcFkJm6gdWhhg= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 60FCF44324; Tue, 4 Nov 2025 12:23:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9585C4CEF7; Tue, 4 Nov 2025 12:23:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762259036; bh=OaulnFfIv9hYj/nauRuDYbAuQXPylBEP9GcGHpiUvAk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=K9Fi45YagBaVytfPhJw99wYzHfVNhv98n74R+fFiWU8QxYsDvSsWBlIN6UqHzHzDM EgagJn9KmmEi3ffbOXmcBMdPe+pwuq0fNlDsVtL3DxfEpg3PzU7uT6lUGHhQ4wbX+N b2Ou5E1SOeTf7/myN14KvVyiJtH9HLgtOmmbUInr6fjXIq97H4IetxHdkF4I2tt5dN 3x/Uq3dQdVTZR+i6g01hAO0DkOSj6LnZuGrpJohlethDz4iBq2jV0w8SR+mlavFOPl BhQTVhIVgdWIVRifdPNl83Upz+rjhgt6glK2tfydNYBic9UqNyuxaKKo4uhajRvBTq uiQSXFDi0MWGA== Message-ID: <52e064b1-819a-47b3-9f4e-7ab0890841e7@kernel.org> Date: Tue, 4 Nov 2025 13:23:49 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 0/4] mm/userfaultfd: modulize memory types To: Mike Rapoport Cc: Peter Xu , Lorenzo Stoakes , "Liam R. Howlett" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Muchun Song , Nikita Kalyazin , Vlastimil Babka , Axel Rasmussen , Andrew Morton , James Houghton , Hugh Dickins , Michal Hocko , Ujwal Kundur , Oscar Salvador , Suren Baghdasaryan , Andrea Arcangeli , conduct@kernel.org References: <7768bbb5-f060-45f7-b584-95bd73c47146@kernel.org> <5f128cbf-7210-42d9-aca1-0a5ed20928c2@kernel.org> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: ADAAA2000B X-Stat-Signature: gfi7turewaxu36koh4hq1bp5with3rdp X-HE-Tag: 1762259037-921400 X-HE-Meta: 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 FwgZDDZi wqF3M11/k/T7ucFsGZH0vz9TMWI/riDclJ7YR0rF73RSZ5/fkrVH8GblViaqebc2do8OtKcgYDuHm/WC/6Mkomy4XPp09m/b1+mvduErLaCpbz6SWwDEksIvng36HFEfpT9pvP3aWAjjxz7rz0fTHcnjGEY1WnW9b88mUGkQf1frDzGXKyZptH9W7CJ91xpkWZgOCI/bfUq88MpEbjWpJNJJ/pro/hGWKT7TP99G+EQYrDuWmyWPGRwmHs5bGZiKBL7pPgNnDy0XME4L1EwMlJK3ZIxnNLVkCAuq3nIfL8NdQZONmzi1h42BmGvf1McSDJ6Ngm+4xUeEMcggL0NrfZu0Z9HEPMg9zj2Fy X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 04.11.25 08:21, Mike Rapoport wrote: > On Mon, Nov 03, 2025 at 10:27:05PM +0100, David Hildenbrand (Red Hat) wrote: >> >> And maybe that's the main problem here: Liam talks about general uffd >> cleanups while you are focused on supporting guest_memfd minor mode "as >> simple as possible" (as you write below). > > Hijacking for the technical part for a moment ;-) What?! That's crazy :P > > It seems that "as simple as possible" can even avoid data members in struct > vm_uffd_ops, e.g something along these lines: Right, that's certainly even more "minimal". In the end I agree with previous assessment that the original series is not completely a "modulize memory types". If we want to make it easier for guest_memfd to support MFILL_ATOMIC_CONTINUE, then maybe we should focus on that, and only that, for the time being to make progress. -- Cheers David