From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755120Ab3EaPhL (ORCPT ); Fri, 31 May 2013 11:37:11 -0400 Received: from moutng.kundenserver.de ([212.227.17.10]:58761 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753336Ab3EaPhG (ORCPT ); Fri, 31 May 2013 11:37:06 -0400 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: Lee Jones , 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 Date: Fri, 31 May 2013 17:36:44 +0200 Message-ID: <1902994.0Kq6C7Rx1R@wuerfel> User-Agent: KMail/4.10.2 (Linux/3.10.0-rc3-next-20130527+; KDE/4.10.3; x86_64; ; ) In-Reply-To: <20130531151850.GC12488@gmail.com> References: <1370010272-25520-1-git-send-email-lee.jones@linaro.org> <38058740.G1EqTG95pA@wuerfel> <20130531151850.GC12488@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V02:K0:BAmwOP2kV9seu9ugLlRTqxzWz5Wl1XsjOfr5xV1kY8f nZ6GP+f20mexMco0KyMmXVglM03ik3eKStnx7iGCRcsCYmQDhH 8p5bsLCQDa1DSZ6Vw/5pO/RjI+m2eBK0l+6LFhHgR09kP53JEc FD7HnSaMIaM7qaiXAdhZ++MlUdudbyUA26nzA/m9EbkLiYg9ni y+8q7GY+gRINGouiVRrqC5ngzep5roNXGnF4w6aYVg0yr7j5Yi l05ZpyzU8xqcnJLRBdaB8QKFhreurXJ1SQt86tylpf6rE30Gcn 85BgZEy2z52KhNZmxfPNVWVeE9EcZ4f689P0T2zFFkJmuMk+OS uocAXLY0b0jjlA7I8xZU= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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. Arnd