From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
To: Christophe Blaess <mailist@logilin.fr>
Cc: xenomai@xenomai.org
Subject: Re: [Xenomai] question: XENO_OPT_TIMING_SCHEDLAT
Date: Mon, 02 Jul 2012 10:47:38 +0200 [thread overview]
Message-ID: <4FF1602A.5040909@xenomai.org> (raw)
In-Reply-To: <4FF1497F.8080909@logilin.fr>
On 07/02/2012 09:11 AM, Christophe Blaess wrote:
> On 02/07/2012 08:12, Christophe Blaess wrote:
>>
>> But, there's still something weird (I run on a stock xenomai 2.6.0
>> with adeos-ipipe-2.6.38.8-arm-1.18-04.patch, I'll try on a 2.6 git
>> kernel)
>>
>> [Panda]#*echo 2388 > /proc/xenomai/latency*
>> [Panda]#*cat /proc/xenomai/latency*
>> 2386
>> [Panda]#*echo 2386 > /proc/xenomai/latency*
>> [Panda]#*cat /proc/xenomai/latency*
>> 2384
>> [Panda]#*echo 2384 > /proc/xenomai/latency*
>> [Panda]#*cat /proc/xenomai/latency*
>> 2382
>> [Panda]#
>>
>> I suspect something wrong in xnarch_tsc_to_ns()/xnarch_ns_to_tsc()
>> maybe in xnarch_llimd(). I'll investigate more this afternoon.
>>
>>
>
> I see the same behaviour with xenomai 2.6 from git source, using
> adeos-ipipe-2.6.38.8-arm-1.18-08.patch
This is because xnarch_tsc_to_ns and xnarch_ns_to_tsc both round toward
0, and the tsc frequency is not a round number of ticks. I do not think
trying to fix an issue for a difference of 2ns is worth the trouble.
--
Gilles.
prev parent reply other threads:[~2012-07-02 8:47 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-30 10:39 [Xenomai] question: XENO_OPT_TIMING_SCHEDLAT ali hagigat
2012-06-30 10:44 ` Gilles Chanteperdrix
2012-06-30 16:52 ` Christophe Blaess
2012-06-30 17:04 ` Gilles Chanteperdrix
2012-07-01 19:00 ` Christophe Blaess
2012-07-01 19:09 ` Gilles Chanteperdrix
2012-07-01 19:33 ` Gilles Chanteperdrix
2012-07-02 6:12 ` Christophe Blaess
2012-07-02 7:11 ` Christophe Blaess
2012-07-02 8:47 ` Gilles Chanteperdrix [this message]
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