From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (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 0DDFE381AA for ; Wed, 11 Dec 2024 13:51:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733925068; cv=none; b=UNsaWIldB+8hgUP07SSqfN9IF+H1leqiS4lt+ITZhX3ymKJnrTnagmihBms14bo7sMcF2gaVCNiVuanwxAM6/ztCHaYfR6PwpTCuLTXOZaTA122Hjmr5p7PoY2i4STB5OPuLOwRtD7N2gGLk4irHVOIoHHGhtf1YH1oMPHFizQ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733925068; c=relaxed/simple; bh=5qubLMaGuBz29aMyEIFBlCc81fI0ogHv+dJZtbbm9uE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ninqLPXTsOjU+juWZi5FfMRFFlKdiZEElvjgHJti/cvstUnO4/GzIrrSDPfqUXWoLj65xrAnx0TYder+TaAEs8wol9He9RFloK8u0E7t+1FIzZPkUSmt9C/Tzvwuxd4TGSC57MB6vt8+CTfkFN1Eyg+YVDEHt27B4emGU1rdfu8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=bTLCy0es; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="bTLCy0es" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Et/J9SQdT88EyXCsKLWmZ8BwqDw8CUv9dJzq6Y7P/LI=; b=bTLCy0es9Myffa2YtoKYWxYB0l taRrsBab9izJB7hzMLz/dMCekfnIEbpysaxo4UXsLkMUGaT26VpObytEWsdvtLJq6vbBcZBJOgCVm 6uNbdWzwV8AsTjoro3AOS/43rKAYCoHT12Jv+9JNUWARE5kX6fTGQjLj/UMqLiRYIk/iYY5BK+xK7 AOvkTwF7J6Q3FASo3+GnqSZXWcFfV2uv+qMuSFYT5P1vem4lnBd1PfobizDSynEiGADPv7/+w9Zwh sJPBKmVvr7FZgYdPZ8waDzFLpIAR5TuMCzIBGOLLW6dQZ5nfXC85HVz2pVVzWxvprpiYWbA8M15G1 w4e88fug==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:48524) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tLN77-0003zU-2t; Wed, 11 Dec 2024 13:50:54 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.96) (envelope-from ) id 1tLN73-0004CI-1c; Wed, 11 Dec 2024 13:50:49 +0000 Date: Wed, 11 Dec 2024 13:50:49 +0000 From: "Russell King (Oracle)" To: Linus Walleij Cc: Arnd Bergmann , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Arnd Bergmann , linux-mm@kvack.org, linux-rt-devel@lists.linux.dev, Ard Biesheuvel , Clark Williams , Jason Baron , Josh Poimboeuf , Mark Rutland , Matthew Wilcox , Peter Zijlstra , Sebastian Andrzej Siewior , Steven Rostedt Subject: Re: [PATCH 3/4] ARM: drop CONFIG_HIGHPTE support Message-ID: References: <20241210160556.2341497-1-arnd@kernel.org> <20241210160556.2341497-4-arnd@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: Russell King (Oracle) On Wed, Dec 11, 2024 at 02:32:51PM +0100, Linus Walleij wrote: > On Tue, Dec 10, 2024 at 5:06 PM Arnd Bergmann wrote: > > > From: Arnd Bergmann > > > > CONFIG_HIGHPTE was added in linux-2.6.32, a few years before 64-bit > > support. At the time it made sense, as the CONFIG_ARM_LPAE option allowed > > systems with 16GB of memory that made lowmem a particularly scarce > > resource, and the HIGHPTE implementation gave feature parity with 32-bit > > x86 and frv machines. > > > > Since Arm is the last architecture remaining that uses this, and almost > > no 32-bit machines support more than 4GB of RAM, the cost of continuing > > to maintain HIGHPTE seems unjustified, so remove it here to allow > > simplifying the generic page table handling. > > > > Link: https://lore.kernel.org/lkml/20241204103042.1904639-8-arnd@kernel.org/T/#u > > Signed-off-by: Arnd Bergmann > > I'm in favor of this if the x86 patch goes in. We need to get rid > of highmem anyway and this will need to happen sooner or later > either way. Well... I use highmem routinely. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!