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 28E2A101E2; Mon, 8 Jul 2024 11:35:34 +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=1720438534; cv=none; b=rMtvLvHfDZuy2QKdzSjWgf3x4wsSLdifFPctKND5vRswnjbDScJN+2iWXv8Mf+e3/49HDM09N1RdB6QGJ/zIGeo75wYYAzmR4rW2Vf3NoDYQH9HMuAFTHx7D+CWILNeZYWZwjgaaBs9d2ThcHqAbsExYpjCgpqb7S3Gim3W4Wq4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720438534; c=relaxed/simple; bh=0q5Ds8WIeOv5Y3nTVZNg0tKqv7bBejypl3Rg0QFJqmI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=K9WPUCZY0oh592sGKdXVmYB6fysso1qerFhGIAPUJh4200o+E8PqYUocBDGYAYM6hCDUuEZ8HBowjmDAE7wMy55GCmRT8/lB0SaQHuBfaPv5GGtjdzfexNiVY9UH50adyBn8yjEMZJASz8MnInqoHhL6xqYE32nYXBs0Rf1rZLs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XsDoAPbD; 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="XsDoAPbD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ACDD9C116B1; Mon, 8 Jul 2024 11:35:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720438534; bh=0q5Ds8WIeOv5Y3nTVZNg0tKqv7bBejypl3Rg0QFJqmI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XsDoAPbDuJawip0mO7VPHOcAtC8umkEX+3mruYsdiHMQTMSnCjk6khCQQhBFOVU2q szsII3oJXeXPXn/TD1fBgYjrRriwN7ffC0ijh8PvFS/JWshQeFdlZKBesvFDDo5JNp ebFxkePURnK0zM1B3jsYHT4MNNEkTpuSUbDOJ0wqE7eJfaQfSWxRo0vWoC5QTabCIW I9ZALOcwRGl2VBpOZP15lKg6qpE8NWgViVA291vGz6q0ajZOlvg0o3swDvw0f3PyCc eOMz086l52tHH0De4Ngoa9ZI+DYKXoJrjaUifAz9HtEFirAu5kGY4AnRE4k3HNrj2S wF50L1Ci27E9g== Date: Mon, 8 Jul 2024 12:35:25 +0100 From: Will Deacon To: Alistair Popple Cc: dan.j.williams@intel.com, vishal.l.verma@intel.com, dave.jiang@intel.com, logang@deltatee.com, bhelgaas@google.com, jack@suse.cz, jgg@ziepe.ca, catalin.marinas@arm.com, mpe@ellerman.id.au, npiggin@gmail.com, dave.hansen@linux.intel.com, ira.weiny@intel.com, willy@infradead.org, djwong@kernel.org, tytso@mit.edu, linmiaohe@huawei.com, david@redhat.com, peterx@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, jhubbard@nvidia.com, hch@lst.de, david@fromorbit.com Subject: Re: [PATCH 13/13] mm: Remove devmap related functions and page table bits Message-ID: <20240708113524.GD11567@willie-the-truck> References: <47c26640cd85f3db2e0a2796047199bb984d1b3f.1719386613.git-series.apopple@nvidia.com> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <47c26640cd85f3db2e0a2796047199bb984d1b3f.1719386613.git-series.apopple@nvidia.com> User-Agent: Mutt/1.10.1 (2018-07-13) On Thu, Jun 27, 2024 at 10:54:28AM +1000, Alistair Popple wrote: > Now that DAX and all other reference counts to ZONE_DEVICE pages are > managed normally there is no need for the special devmap PTE/PMD/PUD > page table bits. So drop all references to these, freeing up a > software defined page table bit on architectures supporting it. > > Signed-off-by: Alistair Popple > --- > Documentation/mm/arch_pgtable_helpers.rst | 6 +-- > arch/arm64/Kconfig | 1 +- > arch/arm64/include/asm/pgtable-prot.h | 1 +- > arch/arm64/include/asm/pgtable.h | 24 +-------- Not only do you exclusively remove code, but you also give us back a pte bit! What's not to like? Acked-by: Will Deacon # arm64 Will