From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752944AbZKCOip (ORCPT ); Tue, 3 Nov 2009 09:38:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751332AbZKCOip (ORCPT ); Tue, 3 Nov 2009 09:38:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:19072 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750861AbZKCOio (ORCPT ); Tue, 3 Nov 2009 09:38:44 -0500 Message-ID: <4AF04076.2070409@redhat.com> Date: Tue, 03 Nov 2009 16:38:46 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.4pre) Gecko/20091014 Fedora/3.0-2.8.b4.fc11 Thunderbird/3.0b4 MIME-Version: 1.0 To: Marcelo Tosatti CC: Gleb Natapov , kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 03/11] Handle asynchronous page fault in a PV guest. References: <1257076590-29559-1-git-send-email-gleb@redhat.com> <1257076590-29559-4-git-send-email-gleb@redhat.com> <20091103141423.GC10084@amt.cnet> <20091103142533.GN27911@redhat.com> <20091103143250.GD10084@amt.cnet> In-Reply-To: <20091103143250.GD10084@amt.cnet> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/03/2009 04:32 PM, Marcelo Tosatti wrote: > Any attempt to access the swapped out data will cause a #PF vmexit, > since the translation is marked as not present. If there's swapin in > progress, you wait for that swapin, otherwise start swapin and wait. > > Its not as efficient as paravirt because you have to wait for a timer > interrupt and the guest scheduler to decide to taskswitch, but OTOH its > transparent. > With a dyntick guest the timer interrupt will come at the end of the time slice, likely after the page has been swapped in. That leaves smp reschedule interrupts and non-dyntick guests. An advantage is that there is one code path for apf and non-apf. Another is that interrupts are processed, improving timekeeping and maybe responsiveness. -- error compiling committee.c: too many arguments to function