From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753097Ab3FCIV1 (ORCPT ); Mon, 3 Jun 2013 04:21:27 -0400 Received: from mail-ee0-f52.google.com ([74.125.83.52]:47857 "EHLO mail-ee0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751197Ab3FCIVX (ORCPT ); Mon, 3 Jun 2013 04:21:23 -0400 Date: Mon, 3 Jun 2013 09:21:17 +0100 From: Lee Jones To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, srinidhi.kasagar@stericsson.com, linux-kernel@vger.kernel.org, linus.walleij@stericsson.com Subject: Re: [PATCH 2/2] ARM: ux500: Enable HIGHMEM in the u8540 defconfig Message-ID: <20130603082117.GD3370@gmail.com> References: <1370010272-25520-1-git-send-email-lee.jones@linaro.org> <38058740.G1EqTG95pA@wuerfel> <20130531151850.GC12488@gmail.com> <1902994.0Kq6C7Rx1R@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1902994.0Kq6C7Rx1R@wuerfel> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 31 May 2013, Arnd Bergmann wrote: > On Friday 31 May 2013 16:18:50 Lee Jones wrote: > > On Fri, 31 May 2013, Arnd Bergmann wrote: > > > > > On Friday 31 May 2013 15:24:32 Lee Jones wrote: > > > > In order to utilise all of the memory located on ux500 based devices > > > > we have to enable HIGHMEM. Without it the kernel truncates memory down > > > > to what's left after the PAGE_OFFSET has been applied, which doesn't > > > > leave an awful lot, especially if we're running large rootfs' such > > > > as full Linux desktop distributions or Android. > > > > > > > > Signed-off-by: Lee Jones > > > > > > How much memory do those devices have? Enabling HIGHMEM is quite expensive. > > > > Another 1GB. > > You mean you have 2GB total or 1.75GB? You could just use We have 2GB in total. > CONFIG_VMSPLIT_2G to an extra GB compared to the default, which > is what vexpress, imx and s5p already do, but you still have to > put the vmalloc area in the low 2GB then. Isn't this for 4GB systems? -- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog