From mboxrd@z Thu Jan 1 00:00:00 1970 From: Erik Rull Subject: Re: Interrupt Assignment on host Date: Thu, 05 Nov 2009 20:09:11 +0100 Message-ID: <4AF322D7.8080509@rdsoftware.de> References: <4AE8B499.7030201@rdsoftware.de> <4AEDAC47.8000908@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" To: Avi Kivity Return-path: Received: from moutng.kundenserver.de ([212.227.126.177]:50030 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758506AbZKETJN (ORCPT ); Thu, 5 Nov 2009 14:09:13 -0500 In-Reply-To: <4AEDAC47.8000908@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > On 10/28/2009 11:16 PM, Erik Rull wrote: >> Hi all, >> >> after several tests it seems that the interrupt assignment on the host >> systems influences the kvm performance drastically. If eth0, video and >> usb >> are on seperate interrupts the perfomance is way better than if they are >> shared (that means on the same one). >> >> Normally this should not matter. But why is it within kvm? Does kvm >> somehow >> hook up into the interrupt service routines? > > No. > >> My guest is Windows XP SP3. > > Can you describe how performance suffers? > > Please provide vmstat (for host int/sec) and "kvm_stat -l -f > 'exits|irq_exits'" output. > I'm sorry, but my target system has no python installed. Any ideas how to do that manually? - Erik