From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: Two dead-lock situation occurs on 32bit HVM SMP Windows Date: Tue, 14 Nov 2006 17:56:55 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Li, Xin B" , Keir Fraser , "Xin, Xiaohui" , xen-devel@lists.xensource.com Cc: "Mallick, Asit K" , "Tian, Kevin" , "Li, Susie" , "He, Qing" , "Nakajima, Jun" List-Id: xen-devel@lists.xenproject.org On 14/11/06 17:42, "Li, Xin B" wrote: >> Any idea what it's trying to access? Presumably nothing is >> mapped up there >> so it just gets all-ones back from reads? I'm surprised it >> would be doing >> lots of accesses to totally unused memory space. That tends to >> be fairly >> slow even on native hardware. >> > > that are from detecting if a guest page table page is no longer a page > table page, like in validate_gl4e. I'll leave it to Tim to decide what the best thing to do here is. But I'm sure we don't need a max_gpfn parameter. Xen could maintain its own highwater mark, updated by the alloc_p2m path, if it needs it. -- Keir