From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jes Sorensen Subject: Re: Enhance perf to support KVM Date: Fri, 26 Feb 2010 14:57:07 +0100 Message-ID: <4B87D333.6020800@redhat.com> References: <1267089644.12790.74.camel@laptop> <1267152599.1726.76.camel@localhost> <20100226090147.GH15885@elte.hu> <4B879A2F.50203@redhat.com> <20100226103545.GA7463@elte.hu> <4B87A6BF.3090301@redhat.com> <20100226111734.GE7463@elte.hu> <4B87B407.2070309@redhat.com> <20100226124646.GB19476@elte.hu> <4B87C494.4090306@redhat.com> <20100226131614.GB2518@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Avi Kivity , "Zhang, Yanmin" , Peter Zijlstra , ming.m.lin@intel.com, sheng.yang@intel.com, KVM General , Zachary Amsden , Gleb Natapov , Arnaldo Carvalho de Melo , Fr??d??ric Weisbecker , Thomas Gleixner , "H. Peter Anvin" , Peter Zijlstra , Arjan van de Ven To: Ingo Molnar Return-path: Received: from mx1.redhat.com ([209.132.183.28]:19344 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936265Ab0BZN5k (ORCPT ); Fri, 26 Feb 2010 08:57:40 -0500 In-Reply-To: <20100226131614.GB2518@elte.hu> Sender: kvm-owner@vger.kernel.org List-ID: On 02/26/10 14:16, Ingo Molnar wrote: > > * Avi Kivity wrote: > >>> That was not what i suggested tho. tools/kvm/ would work plenty fine. >> >> I'll wait until we have tools/libc and tools/X. After all, they affect a >> lot more people and are concerned with a lot more kernel/user interfaces >> than kvm. > > So your answer can be summed up as: 'we wont do what makes sense technically > because others suck even more' ? Well in this discussion what makes sense technically differs depending on who you ask. I will argue that emulating the MSR access doesn't make sense technically because there is no fixed specification we can rely on, since the spec seems to change randomly with every cpu family release from Inte. In addition the overhead is making the resulting numbers less if at all interesting. Jes