From mboxrd@z Thu Jan 1 00:00:00 1970 From: Reeted Subject: Re: [libvirt] Qemu/KVM is 3x slower under libvirt Date: Thu, 29 Sep 2011 12:16:33 +0200 Message-ID: <4E844581.2000902@shiftmail.org> References: <4E82118D.2010702@shiftmail.org> <20110928075138.GC21102@redhat.com> <4E82E6AF.5070009@shiftmail.org> <20110928092859.GO21102@redhat.com> <4E82ED8D.10004@shiftmail.org> <20110929003923.GC19141@sequoia.sous-sol.org> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Daniel P. Berrange" , kvm@vger.kernel.org, libvir-list@redhat.com To: Chris Wright Return-path: Received: from blade3.isti.cnr.it ([194.119.192.19]:52979 "EHLO BLADE3.ISTI.CNR.IT" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751355Ab1I2KRd (ORCPT ); Thu, 29 Sep 2011 06:17:33 -0400 Received: from [192.168.1.115] (firewall.itb.cnr.it [155.253.6.254]) by mx.isti.cnr.it (PMDF V6.5-x5 #31826) with ESMTPSA id <01O6MIIJE95GY0VY3P@mx.isti.cnr.it> for kvm@vger.kernel.org; Thu, 29 Sep 2011 12:16:32 +0200 (MEST) In-reply-to: <20110929003923.GC19141@sequoia.sous-sol.org> Sender: kvm-owner@vger.kernel.org List-ID: On 09/29/11 02:39, Chris Wright wrote: > Can you help narrow down what is happening during the additional 12 > seconds in the guest? For example, does a quick simple boot to single > user mode happen at the same boot speed w/ and w/out vhost_net? Not tried (would probably be too short to measure effectively) but I'd guess it would be the same as for multiuser, see also the FC6 sub-thread > I'm guessing (hoping) that it's the network bring-up that is slow. > Are you using dhcp to get an IP address? Does static IP have the same > slow down? It's all static IP. And please see my previous post, 1 hour before yours, regarding Fedora Core 6: the bring-up of eth0 in Fedora Core 6 is not particularly faster or slower than the rest. This is an overall system slowdown (I'd say either CPU or disk I/O) not related to the network (apart from being triggered by vhost_net).