Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752113Ab0DOKol (ORCPT ); Thu, 15 Apr 2010 06:44:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:27572 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751261Ab0DOKok (ORCPT ); Thu, 15 Apr 2010 06:44:40 -0400 Message-ID: <4BC6EDFF.3000702@redhat.com> Date: Thu, 15 Apr 2010 13:44:15 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Thunderbird/3.0.4 MIME-Version: 1.0 To: Joerg Roedel CC: "Zhang, Yanmin" , Ingo Molnar , Peter Zijlstra , Sheng Yang , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Marcelo Tosatti , Jes Sorensen , Gleb Natapov , Zachary Amsden , zhiteng.huang@intel.com, tim.c.chen@intel.com, Arnaldo Carvalho de Melo Subject: Re: [PATCH V3] perf & kvm: Enhance perf to collect KVM guest os statistics from host side References: <1902387910.2078.435.camel@ymzhang.sh.intel.com> <4BC588CF.5010507@redhat.com> <1902445479.2078.458.camel@ymzhang.sh.intel.com> <4BC6C8CD.1020801@redhat.com> <1902473858.2078.481.camel@ymzhang.sh.intel.com> <20100415090403.GA12697@8bytes.org> <4BC6D7C8.9060302@redhat.com> <20100415094407.GB12697@8bytes.org> <4BC6E0D9.1090202@redhat.com> <20100415104051.GC12697@8bytes.org> In-Reply-To: <20100415104051.GC12697@8bytes.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1086 Lines: 26 On 04/15/2010 01:40 PM, Joerg Roedel wrote: > >> That means an NMI that happens outside guest code (for example, in the >> mmu, or during the exit itself) would be counted as if in guest code. >> > Hmm, true. The same is true for an NMI that happens between VMSAVE and > STGI but that window is smaller. Anyway, I think we don't need the > busy-wait loop. The NMI should be executed at a well defined point and > we set the cpu_var back to NULL after that point. > The point is not well defined. Considering there are already at least two implementations svm, I don't want to rely on implementation details. We could tune the position of the loop so that zero iterations are executed on the implementations we know about. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/