From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from kevlar.burdell.org (kevlar.burdell.org [66.92.73.214]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 96C2567B90 for ; Wed, 19 Jul 2006 14:47:19 +1000 (EST) Date: Wed, 19 Jul 2006 00:47:11 -0400 From: Sonny Rao To: Chris Friesen Subject: Re: kernel memory map/usage/holes? Message-ID: <20060719044711.GA21794@kevlar.burdell.org> References: <44BBEDE1.3040004@nortel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <44BBEDE1.3040004@nortel.com> Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Jul 17, 2006 at 02:06:57PM -0600, Chris Friesen wrote: > > I've got a Maple board with 4GB of memory running a modified 2.6.10 > kernel. When it boots, I see the following in the logs: > > > Top of RAM: 0x180000000, Total RAM: 0x100000000 > On node 0 totalpages: 1048576 > DMA zone: 1048576 pages, LIFO batch:16 > Normal zone: 0 pages, LIFO batch:1 > HighMem zone: 0 pages, LIFO batch:1 > > > Then a bit later, I see: > > > Memory: 4006976k/6291456k available (3408k kernel code, 2284124k > reserved, 1656k data, 448k bss, 220k init) > > > > 1048576 pages works out to 4194304kB, so what happened to the 187328kB > that is the difference between the "Total RAM" and "Memory:" lines? > We've got an app that wants as much memory as possible, so I need to > explain where this 183MB of memory is being used. I think it's part of the "reserved" category, which includes the MMU hashtable. I'd guess that's where it is. Sonny