From: Carsten Emde <Carsten.Emde@osadl.org>
To: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>,
RT <linux-rt-users@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] [rt-tests] change to cyclictest behavior
Date: Wed, 06 Jan 2010 23:50:34 +0100 [thread overview]
Message-ID: <4B4513BA.5090001@osadl.org> (raw)
In-Reply-To: <20100106162759.1d4d5b57@torg>
Clark,
>> [..]
>> May I ask you to also include the -n option which is almost always
>> needed? This would then give:
>> -S --smp Standard SMP testing (equals -a -t -n -d0),
>> same priority on all threads.
> Yeah, you read my mind. How about -m (mlockall) as well?
Hmm, I think that this one is less obvious. Apparently, there are a
bunch of different opinions on mlockall(). I once heard, for example,
the opinion that mlockall() may - under some conditions - introduce a
performance penalty, but I did not verify that. Many real-time systems
do not have a "swap" line in /etc/fstab; mlockall() is not needed in
such systems. In addition, most today's systems have so much RAM that
swapping became a rather rare event. I hope some other RT-ers who are
more knowledgeable about memory management and swapping can comment on this.
Cyclictest was in use for years, before someone introduced the -m
option. I never used this option.
Carsten.
next prev parent reply other threads:[~2010-01-06 22:51 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-06 19:04 [RFC] [rt-tests] change to cyclictest behavior Clark Williams
2010-01-06 19:39 ` John Kacur
2010-01-06 21:39 ` Carsten Emde
2010-01-06 22:04 ` Clark Williams
2010-01-06 22:24 ` Carsten Emde
2010-01-06 22:27 ` Clark Williams
2010-01-06 22:50 ` Carsten Emde [this message]
2010-01-07 0:30 ` Leyendecker, Robert
2010-01-07 7:09 ` Carsten Emde
2010-01-07 7:23 ` Carsten Emde
2010-01-07 14:47 ` Clark Williams
2010-01-07 14:54 ` Carsten Emde
2010-01-12 16:59 ` Sven-Thorsten Dietrich
2010-01-12 17:04 ` Clark Williams
2010-01-12 17:13 ` Sven-Thorsten Dietrich
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