From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: memory zones and the KVM guest kernel Date: Tue, 24 May 2011 11:04:05 +0300 Message-ID: <4DDB6675.6070002@redhat.com> References: <20110523201956.GG7835@dancer.ca.sandia.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: David Evensky Return-path: Received: from mx1.redhat.com ([209.132.183.28]:57130 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753445Ab1EXIEU (ORCPT ); Tue, 24 May 2011 04:04:20 -0400 In-Reply-To: <20110523201956.GG7835@dancer.ca.sandia.gov> Sender: kvm-owner@vger.kernel.org List-ID: On 05/23/2011 11:19 PM, David Evensky wrote: > Hi, > > When I boot my guest kernel with KVM, the dmesg output says that: > > ... > [ 0.000000] Zone PFN ranges: > [ 0.000000] DMA 0x00000010 -> 0x00001000 > [ 0.000000] DMA32 0x00001000 -> 0x00100000 > [ 0.000000] Normal empty > [ 0.000000] Movable zone start PFN for each node > [ 0.000000] early_node_map[2] active PFN ranges > [ 0.000000] 0: 0x00000010 -> 0x0000009f > [ 0.000000] 0: 0x00000100 -> 0x0007fffd > ... > > Why is the Normal Zone empty? The DMA32 zone covers the first 4GB of memory. If you have less than that (actually less than somewhat less than 4GB), nothing spills over to the normal zone. > Is it possible to have some of the > guest's memory mapped in the Normal zone? -m 8G > Is there a good reference that talks about the normal, movable, > etc. memory zones? I expect Mel Gorman's book covers it. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.