From: Steven Rostedt <rostedt@goodmis.org>
To: Josh Cartwright <joshc@ni.com>
Cc: linux-rt-users@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: Re: 3.14-rt ARM performance regression?
Date: Tue, 27 Jan 2015 23:08:46 -0500 [thread overview]
Message-ID: <20150127230846.12aaf405@gandalf.local.home> (raw)
In-Reply-To: <20150124020341.GA2861@jcartwri.amer.corp.natinst.com>
On Fri, 23 Jan 2015 20:03:41 -0600
Josh Cartwright <joshc@ni.com> wrote:
> Hey folks-
>
> We've recently undertaken an upgrade of our kernel from 3.2-rt to
> 3.14-rt, and have run into a performance regression on our ARM boards.
> We're still in the process of trying to isolate what we can, but
> hopefully someone's already run into this and has a solution or might
> have some useful debugging ideas.
>
> The first test we did was to run cyclictest[1] for comparison:
>
> 3.2.35-rt52
> # Total: 312028761 312028761 624057522
> # Min Latencies: 00010 00011
> # Avg Latencies: 00018 00020
> # Max Latencies: 00062 00066 00066
> # Histogram Overflows: 00000 00000 00000
>
> 3.14.25-rt22
> # Total: 304735655 304735657 609471312
> # Min Latencies: 00013 00013
> # Avg Latencies: 00023 00024
> # Max Latencies: 00086 00083 00086
> # Histogram Overflows: 00000 00000 00000
>
I'm curious if the vanilla kernels (non-rt) show the same regression.
Max latencies for vanilla kernels will probably go through the roof,
but the min and average should give you some hint.
-- Steve
next prev parent reply other threads:[~2015-01-28 4:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-24 2:03 3.14-rt ARM performance regression? Josh Cartwright
2015-01-26 22:28 ` Gratian Crisan
2015-01-28 4:08 ` Steven Rostedt [this message]
2015-01-28 23:28 ` Josh Cartwright
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