From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <46C590D5.1060507@domain.hid>
Date: Fri, 17 Aug 2007 14:13:09 +0200
From: Dirk Eibach <eibach@domain.hid>
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Subject: Re: [Xenomai-help] Time for rt_mutex_acquire
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gilles.chanteperdrix@xenomai.org wrote:
> On 8/17/07, Dirk Eibach <eibach@domain.hid> wrote:
>> gilles.chanteperdrix@xenomai.org wrote:
>>> Dirk Eibach wrote:
>>>  > Hello,
>>>  >
>>>  > I'm wondering how long a rt_mutex_acquire is supposed to take on a PPC405
>>>  > platform. I'm getting times about 50 usec here, which is too much for my
>>>  > application. Is anything wrong in my kernel/xenomai configuration or is
>>>  > this time to expected?
>>>
>>> How do you measure this ? Are you sure the mutex is free when you try to
>>> acquire it ?
>>>
>> I prepared a small testcase. It shows about 8.300 ticks, which is about 30
>> usec on my platform (266MHz).
> 
> Did you try to call ppc_getcounter twice in a raw to measure the
> overhead of this function ?

Calling ppc_getcounter twice in a raw results in 116 ticks.

Cheers.
-- 
Dirk Eibach
Entwicklung
Guntermann & Drunck GmbH Systementwicklung