From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Interrupt Assignment on host Date: Sun, 01 Nov 2009 17:41:59 +0200 Message-ID: <4AEDAC47.8000908@redhat.com> References: <4AE8B499.7030201@rdsoftware.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" To: Erik Rull Return-path: Received: from mx1.redhat.com ([209.132.183.28]:17307 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752838AbZKAPmC (ORCPT ); Sun, 1 Nov 2009 10:42:02 -0500 In-Reply-To: <4AE8B499.7030201@rdsoftware.de> Sender: kvm-owner@vger.kernel.org List-ID: 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. -- error compiling committee.c: too many arguments to function