From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: I/O performance of VirtIO Date: Thu, 22 Oct 2009 18:29:14 +0200 Message-ID: <4AE0885A.1080304@redhat.com> References: <20091012204901.GA10688@nightfall.luchs.at> <4AD3A38D.3090102@msgid.tls.msk.ru> <4AD41FB8.6000209@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Michael Tokarev , =?ISO-8859-1?Q?Ren=E9_Pfeiffer?= , kvm@vger.kernel.org To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:47596 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755595AbZJVQbH (ORCPT ); Thu, 22 Oct 2009 12:31:07 -0400 In-Reply-To: <4AD41FB8.6000209@web.de> Sender: kvm-owner@vger.kernel.org List-ID: On 10/13/2009 08:35 AM, Jan Kiszka wrote: > It can be particularly slow if you use in-kernel irqchips and the > default NIC emulation (up to 10 times slower), some effect I always > wanted to understand on a rainy day. So, when you actually want -net > user, try -no-kvm-irqchip. > This might be due to a missing SIGIO or SIGALRM; -no-kvm-irqchip generates a lot of extra signals and thus polling opportunities. I see 300kB/sec from slirp; always assumed it was due to missing tcp features. -- error compiling committee.c: too many arguments to function