From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Page Eviction Algorithm Date: Thu, 28 Oct 2010 10:44:28 +0200 Message-ID: <4CC937EC.9010000@redhat.com> References: <4CC6ADF1.9000805@redhat.com> <4CC6D292.3050703@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Prasad Joshi Return-path: Received: from mx1.redhat.com ([209.132.183.28]:7673 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750705Ab0J1Ioc (ORCPT ); Thu, 28 Oct 2010 04:44:32 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 10/26/2010 03:31 PM, Prasad Joshi wrote: > On Tue, Oct 26, 2010 at 2:07 PM, Avi Kivity wrote: > > On 10/26/2010 12:42 PM, Prasad Joshi wrote: > >> > >> Thanks a lot for your reply. > >> > >> On Tue, Oct 26, 2010 at 11:31 AM, Avi Kivity wrote: > >> > On 10/26/2010 11:19 AM, Prasad Joshi wrote: > >> >> > >> >> Hi All, > >> >> > >> >> I was just going over TODO list on KVM page. In MMU related TODO I saw > >> >> only page eviction algorithm currently implemented is FIFO. > >> >> > >> >> Is it really the case? > >> > > >> > Yes. > >> > > >> >> If yes I would like to work on it. Can someone > >> >> let me know the place where the FIFO code is implemented? > >> > > >> > Look at the code that touches mmu_active_list. > >> > > >> > FWIW improving the algorithm is not critically important. It's rare > >> > that > >> > mmu shadow pages need to be evicted. > >> > >> I would be doing a University project on Virtualization. I would like > >> to work on Linux kernel and KVM. I was looking over the TODO list on > >> KVM wiki. > >> > >> Can you please suggest me something that would add value to KVM? > >> > > > > O(1) write protection (on the TODO page) is interesting and important. It's > > difficult, so you may want to start with O(1) invalidation. > > I am not sure if I can understand what exactly is a MMU invalidation. > Is it cache invalidation or TLB invalidation? Can you please > elaborate. I am really sorry if I am asking a silly question. Invalidation of all shadow page tables. The current code which does this is in kvm_mmu_zap_all(). -- error compiling committee.c: too many arguments to function