Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756299Ab0DFU2g (ORCPT ); Tue, 6 Apr 2010 16:28:36 -0400 Received: from terminus.zytor.com ([198.137.202.10]:53129 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752927Ab0DFU23 (ORCPT ); Tue, 6 Apr 2010 16:28:29 -0400 Message-ID: <4BBB972B.1030600@zytor.com> Date: Tue, 06 Apr 2010 13:18:51 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Thunderbird/3.0.4 MIME-Version: 1.0 To: Frank Hu CC: Joel Fernandes , hayfeng Lee , linux-kernel@vger.kernel.org, linux-kernel@zh-kernel.org, kernelnewbies@nl.linux.org Subject: Re: why choose 896MB to the start point of ZONE_HIGHMEM References: <4BBB7AC9.5060008@zytor.com> <4BBB8F07.60401@zytor.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 766 Lines: 19 On 04/06/2010 01:15 PM, Frank Hu wrote: > > thought that you can only configure how to split the VM like 1G/3G or > 2G/2G. But the DMA zone size, the 128MB space for I/O is not > configurable. The NORMAL zone size will be deducted based on the VM > Split and some hard coded DMA zone and 128 MB space size. > > I am not a guru in this space... so I might be wrong. And you are. The vmalloc zone (not DMA zone -- that's something entirely different) is configurable via the vmalloc= kernel command line option. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/