From mboxrd@z Thu Jan 1 00:00:00 1970 From: Izik Eidus Subject: Re: Automatic page sharing/consolidation Date: Wed, 16 Apr 2008 15:51:22 +0300 Message-ID: <4805F64A.5070800@qumranet.com> References: <20080416013033.GA3057@nibiru.local> <4805E5E9.4080402@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: weigelt@metux.de, linux kernel list , kvm-devel To: Avi Kivity Return-path: In-Reply-To: <4805E5E9.4080402@qumranet.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Avi Kivity wrote: > Enrico Weigelt wrote: >> Hi folks, >> >> I'm using dozens of VE's / jails to separate applications >> (even complete webapps w/ their own httpd) for easier maintenance >> and better security. But this tends to consume a lot of memory, >> since code sharing (.so's) cannot take effect here (each jail/VE >> has it's completely own tree). >> Now I wonder if it might be possible to let the kernel automatically >> find out equal pages and map them together. >> A little compasion showed up that at least 50% of the code could be >> shared (maybe more with some tuning, and maybe even data). So it's >> (IMHO) really worth it. >> >> Would this be possible ? What had to be done for this ? >> > > Izik (copied) is working on this for kvm. Results so far are very > encouraging, but currently merged pages are not swappable. > we have module that posted with kernel patchs in the mm list, you can actualy run it and play with it there were some bugs that we fixed with it, but i am still not sending it, beacuse i change there quite alot of things in order to get swapping possible for the pages that are shared. -- woof.