From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: mmu notifiers Date: Sat, 12 Jan 2008 21:51:56 +0200 Message-ID: <47891A5C.8060907@qumranet.com> References: <20080109181908.GS6958@v2.random> <47860512.3040607@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Daniel J Blueman , Andrea Arcangeli To: Christoph Lameter Return-path: In-Reply-To: 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 Christoph Lameter wrote: > On Thu, 10 Jan 2008, Avi Kivity wrote: > > >> Actually sharing memory is possible even without this patch; one simply >> mmap()s a file into the address space of both guests. Or are you referring to >> something else? >> > > A file from where? If a file is read by two guests then they will have > distinct page structs. > > Two kvm instances mmap() the file (from anywhere) into the guest address space. That memory is shared, and will be backed by the same page structs at the same offset. -- Any sufficiently difficult bug is indistinguishable from a feature. ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <47891A5C.8060907@qumranet.com> Date: Sat, 12 Jan 2008 21:51:56 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [kvm-devel] mmu notifiers References: <20080109181908.GS6958@v2.random> <47860512.3040607@qumranet.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Andrea Arcangeli , kvm-devel@lists.sourceforge.net, linux-mm@kvack.org, Daniel J Blueman List-ID: Christoph Lameter wrote: > On Thu, 10 Jan 2008, Avi Kivity wrote: > > >> Actually sharing memory is possible even without this patch; one simply >> mmap()s a file into the address space of both guests. Or are you referring to >> something else? >> > > A file from where? If a file is read by two guests then they will have > distinct page structs. > > Two kvm instances mmap() the file (from anywhere) into the guest address space. That memory is shared, and will be backed by the same page structs at the same offset. -- Any sufficiently difficult bug is indistinguishable from a feature. -- 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