From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Guest virtual CPUs limited to only 50% of host CPU Date: Tue, 05 Apr 2011 12:03:39 +0300 Message-ID: <4D9ADAEB.1030301@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Drew Johnson Return-path: Received: from mx1.redhat.com ([209.132.183.28]:46259 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751382Ab1DEJDo (ORCPT ); Tue, 5 Apr 2011 05:03:44 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 03/31/2011 11:03 PM, Drew Johnson wrote: > Hi, > > I am using Qemu-KVM-0.12.5 This is somewhat old. Try upgrading. > on Intel Xeon (Vt-x enabled) processors and > monitoring the system using htop on the host. On the processors that > are running Qemu-KVM I am seeing a 50/50 split between userspace and > guest ("gu:" in htop). I have pinned the vCPU qemu-kvm threads to > specific host CPUs using taskset. In the guest the CPUs are nearly > 100% userspace in htop. > > Does anyone have ideas on why this is? Is there a way I can get much > higher utilization for the guest virtual CPUs wrt the host? > Please build qemu with --disable-cpu-strip and run 'perf top' to see what's going on. -- error compiling committee.c: too many arguments to function