From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <479859C1.1070301@qumranet.com> Date: Thu, 24 Jan 2008 11:26:25 +0200 From: Izik Eidus MIME-Version: 1.0 Subject: Re: [kvm-devel] [RFC][PATCH 0/5] Memory merging driver for Linux References: <4794C2E1.8040607@qumranet.com> <20080123231037.GA3629@sequoia.sous-sol.org> <479824EA.7070603@qumranet.com> In-Reply-To: <479824EA.7070603@qumranet.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Avi Kivity Cc: Chris Wright , kvm-devel , andrea@qumranet.com, dor.laor@qumranet.com, linux-mm@kvack.org, yaniv@qumranet.com List-ID: Avi Kivity wrote: > Chris Wright wrote: >> * Izik Eidus (izike@qumranet.com) 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. > yes, write faults are getting into do_wp_page() that in turn create a new anonymous/swappable page so it is safe. -- woof. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org