From mboxrd@z Thu Jan 1 00:00:00 1970 From: Segher Boessenkool Subject: Re: the trouble with large pages Date: Fri, 7 Sep 2007 17:00:09 +0200 Message-ID: References: <1189176020.9287.18.camel@basalt> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-ppc-devel , kvm-devel To: Hollis Blanchard Return-path: In-Reply-To: <1189176020.9287.18.camel@basalt> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org > The PowerPC 440 Linux kernel uses 256MB pages for the linear mapping. > When we run that as a guest, those pages would of course need to be > physically contiguous in the host. > Another possibility is to fake out guest large pages by actually using > small pages on the host, and handle the extra faults in KVM without > notifying the guest. That seems like the best plan, for a first shot anyway. Also, even when you do support backing 256MB pages with 256MB pages, you probably still want the small-page backing as a backup in case you run out of large pages. Segher ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/