From: Ingo Molnar <mingo@kernel.org>
To: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org,
Steven Rostedt <rostedt@goodmis.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
Dave Jones <davej@redhat.com>,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: perf/ftrace lockup on 3.12-rc6 with trigger code
Date: Sat, 26 Oct 2013 10:48:36 +0200 [thread overview]
Message-ID: <20131026084836.GC14237@gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.10.1310251726001.31246@vincent-weaver-1.um.maine.edu>
* Vince Weaver <vincent.weaver@maine.edu> wrote:
> I don't know if there are any better ways to try to debug things
> than the printk route. Though that has its own problems as the
> printk's themselves start showing up in the ftrace traces.
One additional brute-force method is earlyprintk=...,keep and
marking the (handful of) earlyprintk functions (and snprintf)
notrace, plus turning off printk itself completely.
That gives a completely instrumentation-free and locking-free
console output function of last resort :-/
Thanks,
Ingo
next prev parent reply other threads:[~2013-10-26 8:48 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-24 17:30 perf/ftrace lockup on 3.12-rc6 with trigger code Vince Weaver
2013-10-24 18:25 ` Vince Weaver
2013-10-25 10:08 ` Steven Rostedt
2013-10-25 10:19 ` Ingo Molnar
2013-10-25 13:17 ` Vince Weaver
2013-10-25 13:12 ` Vince Weaver
2013-10-25 21:36 ` Vince Weaver
2013-10-26 8:48 ` Ingo Molnar [this message]
2013-11-05 18:06 ` Vince Weaver
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