From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756312Ab2GaXnu (ORCPT ); Tue, 31 Jul 2012 19:43:50 -0400 Received: from mga11.intel.com ([192.55.52.93]:8883 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753148Ab2GaXnt (ORCPT ); Tue, 31 Jul 2012 19:43:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="191507619" Date: Wed, 1 Aug 2012 07:43:36 +0800 From: Fengguang Wu To: Steven Rostedt Cc: Avi Kivity , Steven Rostedt , "Paul E. McKenney" , LKML , "kvm@vger.kernel.org" Subject: Re: Testing tracer wakeup_rt: .. no entries found ..FAILED! Message-ID: <20120731234336.GA5526@localhost> References: <20120724090330.GA9830@localhost> <20120724090720.GA10434@localhost> <1343663105.3847.7.camel@fedora> <20120731121759.GA17822@localhost> <5017D19B.5080806@redhat.com> <1343738627.27983.30.camel@gandalf.stny.rr.com> <5017D4AB.3090107@redhat.com> <1343740419.27983.33.camel@gandalf.stny.rr.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1343740419.27983.33.camel@gandalf.stny.rr.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 31, 2012 at 09:13:39AM -0400, Steven Rostedt wrote: > On Tue, 2012-07-31 at 15:50 +0300, Avi Kivity wrote: > > On 07/31/2012 03:43 PM, Steven Rostedt wrote: > > > That would be better. A hypervisor might be real-time capable (with > > some effort kvm can do this), so we don't want to turn off real time > > features just based on that. > > It would only turn off if you enable selftests and the timing falied. If > the kvm had real time features, this most likely would fail anyway. But > that said, here's a patch that should solve this: No luck.. it still fails: [ 2.360068] Testing tracer irqsoff: [ 2.854529] [ 2.854828] =============================== [ 2.855560] [ INFO: suspicious RCU usage. ] [ 2.856266] 3.5.0-00024-g01ff5db-dirty #3 Not tainted [ 2.857182] ------------------------------- [ 2.857933] /c/wfg/linux/include/linux/rcupdate.h:730 rcu_read_lock() used illegally while idle! [ 2.859450] [ 2.859450] other info that might help us debug this: [ 2.859450] [ 2.860874] [ 2.860874] RCU used illegally from idle CPU! [ 2.860874] rcu_scheduler_active = 1, debug_locks = 0 [ 2.862754] RCU used illegally from extended quiescent state! [ 2.863741] 2 locks held by swapper/0/0: [ 2.864377] #0: [ 2.864423] (max_trace_lock){......}, at: [<814f6bfe>] check_critical_timing+0xd7/0x286 [ 2.864423] #1: (rcu_read_lock){.+.+..}, at: [<8116f930>] __update_max_tr+0x0/0x430 [ 2.864423] stack backtrace: [ 2.864423] Pid: 0, comm: swapper/0 Not tainted 3.5.0-00024-g01ff5db-dirty #3 [ 2.864423] Call Trace: [ 2.864423] [<81103a06>] lockdep_rcu_suspicious+0x1c6/0x210 [ 2.864423] [<8116fc9a>] __update_max_tr+0x36a/0x430 [ 2.864423] [<8116f930>] ? tracing_record_cmdline+0x200/0x200 [ 2.864423] [<8117186e>] update_max_tr_single+0x14e/0x2c0 [ 2.864423] [<81170baa>] ? __trace_stack+0x2a/0x40 [ 2.864423] [<814f6d22>] check_critical_timing+0x1fb/0x286 [ 2.864423] [<81013313>] ? default_idle+0x593/0xc30 [ 2.864423] [<81013313>] ? default_idle+0x593/0xc30 [ 2.864423] [<8110a0e7>] ? trace_hardirqs_on+0x27/0x40 [ 2.864423] [<8117ea5e>] time_hardirqs_on+0x1de/0x220 [ 2.864423] [<81013313>] ? default_idle+0x593/0xc30 [ 2.864423] [<81109d6d>] trace_hardirqs_on_caller+0x2d/0x380 [ 2.864423] [<8110a0e7>] trace_hardirqs_on+0x27/0x40 [ 2.864423] [<81013313>] default_idle+0x593/0xc30 [ 2.864423] [<8101692d>] cpu_idle+0x2dd/0x390 [ 2.864423] [<814eb841>] rest_init+0x2f5/0x314 [ 2.864423] [<814eb54c>] ? __read_lock_failed+0x14/0x14 [ 2.864423] [<817a43b4>] start_kernel+0x866/0x87a Thanks, Fengguang