From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC PATCH 0/2] Expose available KVM free memory slot count to help avoid aborts Date: Wed, 26 Jan 2011 11:17:11 +0200 Message-ID: <4D3FE697.4010502@redhat.com> References: <20110121233040.22262.68117.stgit@s20.home> <20110124093241.GA28654@amt.cnet> <4D3D89B1.30300@siemens.com> <1295883899.3230.9.camel@x201> <1295933876.3230.46.camel@x201> <4D3E7D74.1030100@web.de> <1295966492.3230.55.camel@x201> <4D3EE3F8.3020603@redhat.com> <20110125145955.GE15666@redhat.com> <4D3F0974.3040904@redhat.com> <20110125175839.GC17734@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Alex Williamson , Jan Kiszka , Marcelo Tosatti , "kvm@vger.kernel.org" , "ddutile@redhat.com" , "chrisw@redhat.com" To: "Michael S. Tsirkin" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:57720 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752485Ab1AZJRQ (ORCPT ); Wed, 26 Jan 2011 04:17:16 -0500 In-Reply-To: <20110125175839.GC17734@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 01/25/2011 07:58 PM, Michael S. Tsirkin wrote: > On Tue, Jan 25, 2011 at 07:33:40PM +0200, Avi Kivity wrote: > > On 01/25/2011 04:59 PM, Michael S. Tsirkin wrote: > > >On Tue, Jan 25, 2011 at 04:53:44PM +0200, Avi Kivity wrote: > > >> For the other lookups, which we > > >> believe will succeed, we can assume the probablity of a match is > > >> related to the slot size, and sort the slots by page count. > > > > > >Unlikely to be true for assigned device BARs. > > > > We'll have a large slot at 4G+ - EOM, a medium slot at 1M-3G, and > > lots of small slots for BARs and such. > > > > The vast majority of faults will either touch one of the two largest > > slots, or will miss all slots. Relatively few will hit the small > > slots. > > Not if you are using one of the assigned devices and don't > do any faults on memory :) It's impossible not to fault on memory. -- error compiling committee.c: too many arguments to function