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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D77D2CAC583 for ; Tue, 9 Sep 2025 10:37:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=St/jo3/IjoT+/tBd36JJNTe9cJMOpLH/Kfc1GffKIvY=; b=CjmpMgB//2xUpH57CLFt5JodRJ y3jm+aPr4UROdoK2bBol8/g13HSgUU5rgUIzycHvnZ5FNGEEA9HKgnI3x0k2dWN7OEYXLdhkig7mT yNR7xCD3KJPiEEoHaWBfUXfeRXQuwxb8Hxeywk3ypXJiDBum+GL4Ei/LWC0vstnrXs9ALflO566dX FKZzKCrJ4v0zAG5gpG/UMWHwu49lnotdMcwM1mT1VPXx98JQDb9tCHEgfnNxR3LFxCvEbPJ/S8cOz qbkIE23MuFve46pN3RQB7OfalhfDwH3TjedHMLWEmSX5wfftj9L2mb5NHFiT20VvLST4BGxhRT4S5 vuGDg5lg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uvvin-00000006S0U-36tV; Tue, 09 Sep 2025 10:37:09 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uvuNJ-00000005q0R-2OXF for linux-arm-kernel@lists.infradead.org; Tue, 09 Sep 2025 09:10:54 +0000 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-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250909_021053_745494_AFB6F563 X-CRM114-Status: GOOD ( 12.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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