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Subject: Re: runaway latency detection
To: "T. Smith" <tlsmith3777@gmail.com>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
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        Steven Rostedt <rostedt@goodmis.org>, Daniel Wagner <wagi@monom.org>
References: <94710CE6-857F-424A-9D50-8569D6282367@gmail.com>
Cc: linux-kernel@vger.kernel.org
From: Nikolay Borisov <n.borisov.lkml@gmail.com>
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Date: Sat, 20 Aug 2016 20:54:23 +0300
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On 20.08.2016 20:03, T. Smith wrote:
> The goal is to isolate causes of indeterminism when using the PREEMPT_RT kernel configuration with full preemption and to characterize latency and jitter using ftrace, any recommendations?

What hardware is it ? If it's x86 it's entirely possible you are seeing
SMI. Perhaps you should look into disabling those if you are on x86?