From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Zanussi Subject: Re: [RFC][PATCH 00/21] tracing: Inter-event (e.g. latency) support Date: Wed, 08 Feb 2017 17:28:50 -0600 Message-ID: <1486596530.2871.22.camel@tzanussi-mobl.amr.corp.intel.com> References: <20170208150109.5919a2ea@gandalf.local.home> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: tglx@linutronix.de, mhiramat@kernel.org, namhyung@kernel.org, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org To: Steven Rostedt Return-path: Received: from mga01.intel.com ([192.55.52.88]:40740 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752047AbdBHX3S (ORCPT ); Wed, 8 Feb 2017 18:29:18 -0500 In-Reply-To: <20170208150109.5919a2ea@gandalf.local.home> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Wed, 2017-02-08 at 15:01 -0500, Steven Rostedt wrote: > On Wed, 8 Feb 2017 11:24:56 -0600 > Tom Zanussi wrote: > > > # echo 'wakeup_latency lat=sched_switch:wakeup_lat \ > > pid=sched_switch:woken_pid \ > > prio=sched_switch:woken_prio' >> \ > > /sys/kernel/debug/tracing/synthetic_events > > I applied all your patches, did the above and then: > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000034 > IP: free_synthetic_event+0x46/0xb0 > PGD 0 > OK, well, the problem is actually the '\' 'continuation' characters in the above string. I'll fix that properly, but in the meantime, removing those chars in the documentation strings will let you try it out i.e. # echo 'wakeup_latency lat=sched_switch:wakeup_lat pid=sched_switch:woken_pid prio=sched_switch:woken_prio' >> /sys/kernel/debug/tracing/synthetic_events Tom