From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <47860512.3040607@qumranet.com> Date: Thu, 10 Jan 2008 13:44:18 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [kvm-devel] mmu notifiers References: <20080109181908.GS6958@v2.random> 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 Wed, 9 Jan 2008, Andrea Arcangeli wrote: > > >> This patch is a first basic implementation of the mmu notifiers. More >> methods can be added in the future. >> >> In short when the linux VM decides to free a page, it will unmap it >> from the linux pagetables. However when a page is mapped not just by >> the regular linux ptes, but also from the shadow pagetables, it's >> currently unfreeable by the linux VM. >> > > Such a patch would also address issues that SGI has with exporting > mappings via XPMEM. Plus a variety of other uses. Go ahead and lets do > more in this area. > > Are the KVM folks interested in exporting memory from one guest to > another? That may also become possible with some of the work that we have > in progress and that also requires a patch like this. > > 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? The patch does enable some nifty things; one example you may be familiar with is using page migration to move a guest from one numa node to another. -- error compiling committee.c: too many arguments to function -- 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