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 DB4DECA0FED for ; Tue, 9 Sep 2025 09:10:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2C49C8E001A; Tue, 9 Sep 2025 05:10:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 274B98E0015; Tue, 9 Sep 2025 05:10:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 164348E001A; Tue, 9 Sep 2025 05:10:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 00C958E0015 for ; Tue, 9 Sep 2025 05:10:55 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id A1A9413AE72 for ; Tue, 9 Sep 2025 09:10:55 +0000 (UTC) X-FDA: 83869142070.28.9F2FE1A Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf02.hostedemail.com (Postfix) with ESMTP id EA89080005 for ; Tue, 9 Sep 2025 09:10:53 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf02.hostedemail.com: domain of kevin.brodsky@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=kevin.brodsky@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1757409054; 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; bh=St/jo3/IjoT+/tBd36JJNTe9cJMOpLH/Kfc1GffKIvY=; b=274lZzj+mnu/bMliIICsDVFIoevgOSMtcxllFEHW58GzXnkm0JDakdYQ2mO8Ur2P5NKuvU k9GnvE73pm2HaWJlwyAHT4wtaDtOPeM0Q0+mvgY/e0Nxrr/s21tG0PMrRHDR2XOyg46/RR EeJEheRO4xXShrC6Lb1UeMzaOM7dxNk= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf02.hostedemail.com: domain of kevin.brodsky@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=kevin.brodsky@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1757409054; a=rsa-sha256; cv=none; b=VMDuhBZ7fZrbuC6xnWDNnMniPVl+mtuUKRDcsyadFsarzsrdRc+AUu2wngwqfZgEnQZnxh GzvA/594S76x+yHLX8JzdyhedC3gYcwR1K0kGj6jl1Ks0WzijAaFRY7xHPxPfg2vcGhXAt CUCx6933Rxg1q8LyNdhn96zfG2KqPhU= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4A03615A1; Tue, 9 Sep 2025 02:10:44 -0700 (PDT) Received: from [10.57.60.124] (unknown [10.57.60.124]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 358583F63F; Tue, 9 Sep 2025 02:10:37 -0700 (PDT) Message-ID: <652720ae-131e-4de0-bc65-e5c1bdc46186@arm.com> Date: Tue, 9 Sep 2025 11:10:34 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 0/7] Nesting support for lazy MMU mode To: Lorenzo Stoakes Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alexander Gordeev , Andreas Larsson , Andrew Morton , Boris Ostrovsky , Borislav Petkov , Catalin Marinas , Christophe Leroy , Dave Hansen , David Hildenbrand , "David S. Miller" , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Juergen Gross , "Liam R. Howlett" , Madhavan Srinivasan , Michael Ellerman , Michal Hocko , Mike Rapoport , Nicholas Piggin , Peter Zijlstra , Ryan Roberts , Suren Baghdasaryan , Thomas Gleixner , Vlastimil Babka , Will Deacon , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org References: <20250908073931.4159362-1-kevin.brodsky@arm.com> Content-Language: en-GB From: Kevin Brodsky In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: 5osyihwj4iw5j4kbmbwjrnzdr6asxjkh X-Rspam-User: X-Rspamd-Queue-Id: EA89080005 X-Rspamd-Server: rspam04 X-HE-Tag: 1757409053-247887 X-HE-Meta: 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 1Wuad0+A ER90LzgkmExjF5+UJcj9pTQixRDMbsQmVWobqCzyXT8j8GUEgSJ2uPxFUrylns/jq657YScSAIIKFN0uAsXPE2isn+kJL+gSuBVikAZKcKGTbSIC2PFaJ4bPTEjpzkhTHLi9PrcOuzjpRF6o= 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 08/09/2025 18:56, Lorenzo Stoakes wrote: > On Mon, Sep 08, 2025 at 08:39:24AM +0100, Kevin Brodsky wrote: >> When the lazy MMU mode was introduced eons ago, it wasn't made clear >> whether such a sequence was legal: >> >> arch_enter_lazy_mmu_mode() >> ... >> arch_enter_lazy_mmu_mode() >> ... >> arch_leave_lazy_mmu_mode() >> ... >> arch_leave_lazy_mmu_mode() >> >> It seems fair to say that nested calls to >> arch_{enter,leave}_lazy_mmu_mode() were not expected, and most >> architectures never explicitly supported it. > > This is compiling with CONFIG_USERFAULTFD at all commits and series is > compiling with allmodconfig plus all mm selftests are passing so from my > side this looks good, thanks for addressing issues and rebasing! :) Great thank you for that extensive testing, very appreciated! Shall I add your Reviewed-by to the whole series? - Kevin