From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC][PATCH 0/5] Memory merging driver for Linux Date: Thu, 24 Jan 2008 07:40:58 +0200 Message-ID: <479824EA.7070603@qumranet.com> References: <4794C2E1.8040607@qumranet.com> <20080123231037.GA3629@sequoia.sous-sol.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: andrea-atKUWr5tajBWk0Htik3J/w@public.gmane.org, yaniv-atKUWr5tajBWk0Htik3J/w@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, kvm-devel To: Chris Wright Return-path: In-Reply-To: <20080123231037.GA3629-JyIX8gxvWYPr2PDY2+4mTGD2FQJk+8+b@public.gmane.org> 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 Chris Wright wrote: > * Izik Eidus (izike-atKUWr5tajBWk0Htik3J/w@public.gmane.org) wrote: > >> this module find this identical data (pages) and merge them into one >> single page >> this new page is write protected so in any case the guest will try to >> write to it do_wp_page will duplicate the page >> > > What happens if you've merged more pages than you can recover on write > faults? > You start to swap. Just like Linux when you start to write on fork()ed memory. A management application may start taking measures, like inflating balloons and migrating to other hosts, but swapping is needed as a last resort measure. -- Any sufficiently difficult bug is indistinguishable from a feature. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/