From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757581AbZHGLd6 (ORCPT ); Fri, 7 Aug 2009 07:33:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757559AbZHGLd5 (ORCPT ); Fri, 7 Aug 2009 07:33:57 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:55987 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752371AbZHGLd4 (ORCPT ); Fri, 7 Aug 2009 07:33:56 -0400 Date: Fri, 7 Aug 2009 13:33:49 +0200 From: Ingo Molnar To: "Metzger, Markus T" Cc: Peter Zijlstra , "tglx@linutronix.de" , "hpa@zytor.com" , "markus.t.metzger@gmail.com" , "linux-kernel@vger.kernel.org" Subject: Re: [patch] x86, perf_counter, bts: add bts to perf_counter Message-ID: <20090807113349.GA31673@elte.hu> References: <20090804111412.GA20942@elte.hu> <20090804113555.GA28198@elte.hu> <928CFBE8E7CB0040959E56B4EA41A77EC1BFEEE3@irsmsx504.ger.corp.intel.com> <1249633282.32113.613.camel@twins> <928CFBE8E7CB0040959E56B4EA41A77EC1BFEFEB@irsmsx504.ger.corp.intel.com> <20090807103127.GA23139@elte.hu> <20090807103610.GA23728@elte.hu> <928CFBE8E7CB0040959E56B4EA41A77EC1BFF02D@irsmsx504.ger.corp.intel.com> <928CFBE8E7CB0040959E56B4EA41A77EC1BFF048@irsmsx504.ger.corp.intel.com> <20090807112421.GB30014@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090807112421.GB30014@elte.hu> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar wrote: > * Metzger, Markus T wrote: > > > Ingo, what exactly do you mean by "locks up"? Is the kernel > > hanging or is perf record hanging? > > it was a hard hang - box was not pingable, etc. the moment i tried kernel-mode BTS tracing (i.e. -e branches, not -e branches:u) it hung hard again: titan:~> perf record -o /dev/null -f -e branches -c 1 ./loop_1b_instructions this time i had a serial console attached - there's a perfcounters warning prior the hang - attached below. Peter, any ideas? Ingo [ 995.556131] ------------[ cut here ]------------ [ 995.557128] WARNING: at kernel/perf_counter.c:1191 __perf_counter_task_sched_out+0x48/0x6b() [ 995.557128] Hardware name: [ 995.557128] Modules linked in: [ 995.557128] Pid: 2008, comm: perf Tainted: G M 2.6.31-rc5-tip #1350 [ 995.557128] Call Trace: [ 995.557128] [] ? __perf_counter_task_sched_out+0x48/0x6b [ 995.557128] [] warn_slowpath_common+0x77/0xa4 [ 995.557128] [] warn_slowpath_null+0xf/0x11 [ 995.557128] [] __perf_counter_task_sched_out+0x48/0x6b [ 995.557128] [] perf_counter_task_tick+0x61/0x9d [ 995.557128] [] scheduler_tick+0x112/0x237 [ 995.557128] [] update_process_times+0x4f/0x60 [ 995.557128] [] tick_sched_timer+0x6e/0x8e [ 995.557128] [] __run_hrtimer+0x71/0xa5 [ 995.557128] [] hrtimer_interrupt+0xef/0x149 [ 995.557128] [] smp_apic_timer_interrupt+0x83/0x96 [ 995.557128] [] apic_timer_interrupt+0x13/0x20 [ 995.557128] [] ? __log_space_left+0x0/0x2f [ 995.557128] [] ? start_this_handle+0x302/0x373 [ 995.557128] [] ? lock_page+0x11/0x29 [ 995.557128] [] ? journal_start+0x95/0xc5 [ 995.557128] [] ? ext3_journal_start_sb+0x4a/0x4c [ 995.557128] [] ? ext3_write_begin+0x9c/0x1e2 [ 995.557128] [] ? generic_perform_write+0xb4/0x1a7 [ 995.557128] [] ? generic_file_buffered_write+0x6d/0x10c [ 995.557128] [] ? __generic_file_aio_write_nolock+0x25e/0x292 [ 995.557128] [] ? mntput_no_expire+0x24/0xe8 [ 995.557128] [] ? generic_file_aio_write+0x67/0xc3 [ 995.557128] [] ? ext3_file_write+0x1e/0x9f [ 995.557128] [] ? do_sync_write+0xe7/0x12d [ 995.557128] [] ? show_map_vma+0x1c1/0x1d0 [ 995.557128] [] ? __up_read+0x9e/0xa8 [ 995.557128] [] ? autoremove_wake_function+0x0/0x38 [ 995.557128] [] ? m_stop+0x2b/0x4d [ 995.557128] [] ? security_file_permission+0x11/0x13 [ 995.557128] [] ? vfs_write+0xab/0x105 [ 995.557128] [] ? sys_write+0x47/0x6f [ 995.557128] [] ? system_call_fastpath+0x16/0x1b [ 995.557128] ---[ end trace ff0d385da11eb1c5 ]---