From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [RFC][PATCH 00/21] tracing: Inter-event (e.g. latency) support Date: Wed, 8 Feb 2017 21:14:31 -0500 Message-ID: <20170208211431.467477f5@grimm.local.home> References: <20170208150109.5919a2ea@gandalf.local.home> <1486596530.2871.22.camel@tzanussi-mobl.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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: Tom Zanussi Return-path: In-Reply-To: <1486596530.2871.22.camel@tzanussi-mobl.amr.corp.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org On Wed, 08 Feb 2017 17:28:50 -0600 Tom Zanussi wrote: > 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 Ah, OK. Yeah, I did a cut and paste when entering it. -- Steve