From: "T. Smith" <tlsmith3777@gmail.com>
To: Daniel Bristot de Oliveira <bristot@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Jon Masters <jcm@redhat.com>, Carsten Emde <C.Emde@osadl.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>,
Clark Williams <williams@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
Daniel Wagner <wagi@monom.org>
Cc: linux-kernel@vger.kernel.org
Subject: runaway latency detection
Date: Sat, 20 Aug 2016 12:03:37 -0500 [thread overview]
Message-ID: <94710CE6-857F-424A-9D50-8569D6282367@gmail.com> (raw)
Trying to isolate PREEMPT_RT (full preemption) runaway latency conditions seen when using the cyclictest on the 4.1.8 SMP PREEMPT_RT kernel. Seen average latency of 3uS, but runaway or outlier max latency seems indeterminate. Noted 72uS with one run of the cyclictest for example. Is this a known issue, the cause understood, and is there a patch for this?
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?
next reply other threads:[~2016-08-20 17:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-20 17:03 T. Smith [this message]
2016-08-20 17:54 ` runaway latency detection Nikolay Borisov
[not found] ` <CAChUvXP8Zy4uz95NWFEtF9oU6rHjPZ0Uz5qPMqY1n3i2eBeaSw@mail.gmail.com>
2016-08-21 3:45 ` Steven Rostedt
2016-08-22 2:22 T. Smith
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