From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EBB68275854; Tue, 9 Sep 2025 09:10:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757409055; cv=none; b=t5h2TugzjishSE8NqYk9hWn+ym7gQ0e0MFZLCQkeoZh2k36d4M2Kw0H2dOI1+S3EzogV/sLIL9gr42ctxu0nTJolw23/TGFE21ff8IW5mndIYKIKipTGN6ufPCr/+Qmqmac/3vyoPQjoqw9LRaYO7tzFIQzyZT6AlkpJDOZsr6s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757409055; c=relaxed/simple; bh=hx6F/O2pbkD2iJuvkw1ZAwJxbvLKRvEnkIoGGCOGwCo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=eN3Y5GQ2fXMt4N0dZIe0b0EVEjGJmIpm7Yx3DT0sCsUtIKiq+pmI0AHXMqD7OwhR1SMMIl+Q6xLSUOE+BU99iVbnz7/8UGe6A1l+TpEphKIxUVxp5ypuSTbsiEho6E+pa8+EwSriATWN9CaDik/ORV/lOH40PovahVYZLCF3jfo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 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 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 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