From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752416Ab0C0CJc (ORCPT ); Fri, 26 Mar 2010 22:09:32 -0400 Received: from mailhub129.itcs.purdue.edu ([128.210.5.129]:51121 "EHLO mailhub129.itcs.purdue.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752072Ab0C0CJb (ORCPT ); Fri, 26 Mar 2010 22:09:31 -0400 X-Greylist: delayed 377 seconds by postgrey-1.27 at vger.kernel.org; Fri, 26 Mar 2010 22:09:31 EDT Message-ID: <4BAD675E.3050600@purdue.edu> Date: Fri, 26 Mar 2010 22:03:10 -0400 From: Naresh Rapolu User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Hardware performance events are not counted by "perf" in a 2.6.31.12 KVM guest Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-PMX-Version: 5.5.7.378829 X-PerlMx-Virus-Scanned: Yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, "perf" tool does not count hardware performance events ( cache misses etc) in a KVM guest ( Ubuntu 9.10 karmic, 2.6.31-14-generic kernel) on Xeon 5530 quad-core. The host is 2.6.28 kernel , Ubuntu 8.04 LTS, Hardy. readfile.sh reads in a large file (1430 lines), which should cause cache-misses. root@multicore4-vm3:/usr/src/linux-2.6.31.12/tools/perf# ./perf stat -r 5 -- bash readfile.sh Performance counter stats for 'bash readfile.sh' (5 runs): 11002.207467 task-clock-msecs # 1.042 CPUs ( +- 10.834% ) 3480 context-switches # 0.000 M/sec ( +- 19.017% ) 2238 CPU-migrations # 0.000 M/sec ( +- 29.488% ) 482299 page-faults # 0.044 M/sec ( +- 0.141% ) 0 cycles # 0.000 M/sec ( +- nan% ) 0 instructions # nan IPC ( +- nan% ) 0 cache-references # 0.000 M/sec ( +- nan% ) 0 cache-misses # 0.000 M/sec ( +- nan% ) 10.560510393 seconds time elapsed ( +- 11.401% ) Do I need to make some configuration changes to enable hardware events ? A similar question was posted recently here : http://lkml.org/lkml/2010/3/18/342 but no response ! Any help would be greatly appreciated. Thanks, Naresh Rapolu.