From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751227AbWHBU6N (ORCPT ); Wed, 2 Aug 2006 16:58:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751278AbWHBU6M (ORCPT ); Wed, 2 Aug 2006 16:58:12 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:44219 "EHLO e4.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1751227AbWHBU6L (ORCPT ); Wed, 2 Aug 2006 16:58:11 -0400 Subject: Re: [RFC][PATCH] enable VMSPLIT for highmem kernels From: Dave Hansen To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org In-Reply-To: <20060802205533.CBD06E21@localhost.localdomain> References: <20060802205533.CBD06E21@localhost.localdomain> Content-Type: text/plain Date: Wed, 02 Aug 2006 13:57:56 -0700 Message-Id: <1154552277.7232.37.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.4.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Well, I somehow managed to post that without appending my description. Here goes: The current VMSPLIT Kconfig option is disabled whenever highmem is on. This is a bit screwy because the people who need to change VMSPLIT the most tend to be the ones with highmem and constrained lowmem. So, remove the highmem dependency. But, re-include the dependency for the "full 1GB of lowmem" option. You can't have the full 1GB of lowmem and highmem because of the need for the vmalloc(), kmap(), etc... areas. I thought there would be at least a bit of tweaking to do to get it to work, but everything seems OK. Boot tested on a 4GB x86 machine, and a 12GB 3-node NUMA-Q: elm3b82:~# cat /proc/meminfo MemTotal: 3695412 kB MemFree: 3659540 kB ... LowTotal: 2909008 kB LowFree: 2892324 kB ... elm3b82:~# zgrep PAE /proc/config.gz CONFIG_X86_PAE=y larry:~# cat /proc/meminfo MemTotal: 11845900 kB MemFree: 11786748 kB ... LowTotal: 2855180 kB LowFree: 2830092 kB Signed-off-by: Dave Hansen -- Dave