From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 7D2FA33B6DE; Wed, 12 Nov 2025 13:57:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762955871; cv=none; b=My1s2R+1ak9/Fel8CoHoCSAb1jb8gqkAXNkC9283q2fBNNc1vD0plKt/NRY72pdHbv2vA+MoPvSA7QKobqi9vEgTLWQus+gq5MGhUkPwVh4AIdfnGrNVmX7NseNZ011AMJepwpcymAC98+LYmEd6CTKeyeFESmZbgLMk4p26VUM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762955871; c=relaxed/simple; bh=wyYh5JA+N7mRZY7BRonX9hRu7lWf6kG2xADXz4mWKHk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uv1aX9BmfBZeGBhpauyxqQPZEM4q5xA7kVOgb4Fr6HrVaP41sfAJTMWagwfipBSpDXE7I2X8qNt7mNH3QP4T2blD2X4FTsEU18Mq7Q8yG4RTfJ5FBbvayxJ7coStfDRsvsKVrt8s4iglz/z+jeZe1PtCxKdhXh9ghuVgRmQoeuE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uDdn5b0T; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="uDdn5b0T" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29847C2BCB4; Wed, 12 Nov 2025 13:57:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762955871; bh=wyYh5JA+N7mRZY7BRonX9hRu7lWf6kG2xADXz4mWKHk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=uDdn5b0TMd79Lh5gGh2J4WjGYOU7mL3bVuBbQ/VXgzY4nMQRUASwOOOn1wPdm3Cym W4XE28wEzp5MfEzdP2hqphehcMkmvAS/b8w6wcpUiLZxYE0rCMGLEp+rVCdW9qI4ba ocobM87q4/c0/j7wdbVyzm/yrXe8KetWir7vwxyUiRXtVNS/+8DnZ7OaB4HqMTf7u6 36VSYtBbbyHuGEXAGGvXe/GFkuJFAWR+xBF55ycy4xXYzkSJweCr6O/7vY6qeuk4iJ 2JAYXvNk5KDLXblAvdwOWYLaBc3JfMXId6w7fnEaMQeOyF/yR5GPTl+Yi8z7SCHe3i /nZPR2FUDupLg== Message-ID: Date: Wed, 12 Nov 2025 14:57:32 +0100 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 v4 07/12] mm: enable lazy_mmu sections to nest To: Kevin Brodsky , Ryan Roberts , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Alexander Gordeev , Andreas Larsson , Andrew Morton , Boris Ostrovsky , Borislav Petkov , Catalin Marinas , Christophe Leroy , Dave Hansen , "David S. Miller" , David Woodhouse , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Juergen Gross , "Liam R. Howlett" , Lorenzo Stoakes , Madhavan Srinivasan , Michael Ellerman , Michal Hocko , Mike Rapoport , Nicholas Piggin , Peter Zijlstra , 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, x86@kernel.org References: <20251029100909.3381140-1-kevin.brodsky@arm.com> <20251029100909.3381140-8-kevin.brodsky@arm.com> <999feffa-5d1d-42e3-bd3a-d949f2a9de9d@arm.com> <824bf705-e9d6-4eeb-9532-9059fa56427f@arm.com> <58fd1a6e-f2c4-421c-9b95-dea4b244a515@arm.com> <8f70692c-25a9-4bd0-94ab-43ab435e4b1b@arm.com> 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 >>> >>> I don't really mind either way, but I don't see an immediate use for [C] >>> and [D] - the idea is that the paused section is short and controlled, >>> not made up of arbitrary calls. >> If my thinking above is correct, then I've already demonstrated that this is not >> the case. So I'd be inclined to go with [D] on the basis that it is the most robust. >> >> Keeping 2 nesting counts (enable and pause) feels pretty elegant to me and gives >> the fewest opportunities for surprises. > > Agreed, if we're going to allow enable() within a paused section, then > we might as well allow paused sections to nest too. The use-case is > clear, so I'm happy to go ahead and make those changes. > > David, any thoughts? I don't mind allowing nesting of pause(), so works for me. -- Cheers David