From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: kernel Bug after upgrading to 3.0.2-2 Date: Tue, 02 May 2006 17:21:27 +0200 Message-ID: <44579517.76E4.0078.0@novell.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org >>> Keir Fraser 28.04.06 18:22 >>> > >On 28 Apr 2006, at 17:06, Brian Hays wrote: > >> Already have it set. Here's my grub.conf settings ... >> >> title Xen 3.0 / 2.6.16 >> kernel /xen.gz dom0_mem=200000 >> module /vmlinuz-2.6.16-xen0 root=/dev/sda2 ro > >A little-known fact about PAE Xen is that you really want to use the >lowmem_emergency_pool boot parameter. > >e.g., lowmem_emegency_pool=16M > >Each megabyte of emergency pool will allow you to guarantee to be able >to support 256 processes (counted across all VMs that you are running). >So the above value would be good for 4096 processes. You'll have to >decide what you need to set that parameter to. As I understand it, this is only needed to be this large because xenlinux allocates an entire page for the pgd where 32 bytes would be sufficient (as is done in native Linux). Wouldn't it thus make more sense to work towards a solution where, like on native, the other possible pgdirs on the same page can actually get used. As allocation already goes through a constructor this wouldn't seem this hard. On the other hand, if it's not hard, you would probably have done it already, so I guess I'm missing something here... Jan