From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 8383CDE981 for ; Thu, 22 May 2008 07:25:03 +1000 (EST) Subject: Re: 1 GB lowmem From: Benjamin Herrenschmidt To: Rune Torgersen In-Reply-To: References: Content-Type: text/plain Date: Wed, 21 May 2008 17:24:38 -0400 Message-Id: <1211405078.8297.258.camel@pasglop> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org Reply-To: benh@kernel.crashing.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2008-05-21 at 13:00 -0500, Rune Torgersen wrote: > Hi > > I am trying to enable 1 GB of lowmem on a Freescale 8280. > In arch/ppc this was easilly done by: > CONFIG_ADVANCED_OPTIONS=y > CONFIG_HIGHMEM_START=0xfe000000 > CONFIG_LOWMEM_SIZE_BOOL=y > CONFIG_LOWMEM_SIZE=0x40000000 > CONFIG_KERNEL_START_BOOL=y > CONFIG_KERNEL_START=0xa0000000 > > This does not work in arch/powerpc. CPU hangs as soon as init starts. > Any ideas what to look at, what to change? You probably need to lower TASK_SIZE too. > The reason I want to do this is because I cannot get highmem support to > work when using CONFIG_PREEMPT_RT. > (hitting a bug_on in kmap_atomic) We should look into fixing that :-) Ben.