From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH] shrinker support for the mmu cache Date: Mon, 17 Mar 2008 10:53:32 -0300 Message-ID: <20080317135332.GA4854@dmt> References: <1205345621.16712.4.camel@localhost.localdomain> <20080312225927.GA30597@dmt> <47DD046B.70404@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , kvm-devel To: Avi Kivity Return-path: Content-Disposition: inline In-Reply-To: <47DD046B.70404@qumranet.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org On Sun, Mar 16, 2008 at 01:28:43PM +0200, Avi Kivity wrote: > Marcelo Tosatti wrote: > > On Wed, Mar 12, 2008 at 08:13:41PM +0200, Izik Eidus wrote: > > > >> this patch simply register the mmu cache with the shrinker. > >> > > > > Hi Izik, > > > > Nice. > > > > I think you want some sort of aging mechanism here. Walk through all > > translations of a shadow page clearing the referenced bit of all > > mappings it holds (and moving pages with any accessed translation to the > > head of the list). > > > > While aging is not too hard to do, I don't think it would add much in > practice; we rarely observe mmu shadow pages being recycled due to > memory pressure. So this is mostly helpful for preventing a VM from > pinning memory when under severe memory pressure, where we don't expect > good performance anyway. Issue is that the shrinker callback will not be called only under severe memory pressure, but for normal system pressure too. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/