From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754112AbZGAMYA (ORCPT ); Wed, 1 Jul 2009 08:24:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751514AbZGAMXw (ORCPT ); Wed, 1 Jul 2009 08:23:52 -0400 Received: from fw08.mobotixserver.de ([213.183.84.168]:34982 "EHLO fw08.mobotixserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751092AbZGAMXw (ORCPT ); Wed, 1 Jul 2009 08:23:52 -0400 From: Daniel Kabs To: Linux Kernel Mailing List Subject: adjusting lowmem_reserve_ratio on an embedded system? Date: Wed, 1 Jul 2009 14:23:52 +0200 User-Agent: KMail/1.9.10 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200907011423.52798.daniel.kabs@gmx.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, in tracing a low on memory situation on an embedded system I came across the Documentation/sysctl/vm.txt. There it is advised to change the lowmem_reserve_ratio on systems running without swap. I wonder if this applies for an embedded system running with 256MByte RAM and no swap which is using only one memory zone (ZONE_NORMAL)? I guess no. To understand what the parameter means I read the relevant section from vm.txt and came across the terms "lowmem zone" and "lower zones" and "lowmem memory". I feel dumb. I could not find a concept of "lower zones" (or "upper" zones). What exactly do they mean? Cheers Daniel