From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [patch 00/13] RFC: out of sync shadow Date: Fri, 12 Sep 2008 15:09:06 -0300 Message-ID: <20080912180906.GA3309@dmt.cnet> References: <20080906184822.560099087@localhost.localdomain> <48C9EA78.3000103@cisco.com> <20080912115120.GA20282@dmt.cnet> <48CA86C3.8020800@cisco.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: "David S. Ahern" Return-path: Received: from mx1.redhat.com ([66.187.233.31]:49223 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751803AbYILSKG (ORCPT ); Fri, 12 Sep 2008 14:10:06 -0400 Content-Disposition: inline In-Reply-To: <48CA86C3.8020800@cisco.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Sep 12, 2008 at 09:12:03AM -0600, David S. Ahern wrote: > > > Marcelo Tosatti wrote: > > On Thu, Sep 11, 2008 at 10:05:12PM -0600, David S. Ahern wrote: > > > > David, > > > > Please reload the kvm-intel module with "bypass_guest_pf=0" option. > > > > > > DOH. You mentioned that in your description, and I forgot to disable it. > Works fine now. > > Guest behavior is amazing. After 30 min of uptime, kscand shows only > 17secs of cpu usage. Before, kscand was hitting over a minute after > about 10 minutes of uptime. Great. Note that its not fully optimized for the RHEL3 highpte kscand case, which calls invlpg for present pagetable entries. The current patchset simply invalidates the shadow on invlpg, meaning that the next access will cause a pagefault exit. It can instead read the guest pte and prefault, saving one exit per test-and-clear-accessed operation.