From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4624D598.5070203@domain.hid> Date: Tue, 17 Apr 2007 16:11:36 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <5C40CD1E4697424ABDE3AC57CF1B22C603221037@domain.hid> In-Reply-To: <5C40CD1E4697424ABDE3AC57CF1B22C603221037@domain.hid> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] Perfs and rt alarms questions. List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "RAKOTOSALAMA, Nirilanto" Cc: xenomai@xenomai.org RAKOTOSALAMA, Nirilanto wrote: > Hello everybody. > > I managed to compile a stable kernel (the Scalability O(1) scheduler options seems to make my system freeze) > xenomai 2.3.1 and vanilla 2.6.20.4, gcc 4.1.1 on FC6. > > I'm programming and testing a xenomai support for a timer library using rt_alarm. The test program > lauches the timer periodically and calculate the precision (difference between theoretical and practical results). > > When I launch the latency test, the max latency I have doesn't exceed 10us. So I supposed the precision shouldn't > exceed 10 to 20us as well, No ? But sometimes, the precision exceed 30 to 60us. Is it normal ? > Something wrong in the way I use rt alarms ? in the kernel configuration ? > > I attach : > - .config > - tests results with overtime with this actual config > - tests results without overtime I had with an old config (unfortunately I cannot restore it). The precision was less than > 8us, I didn't enable xeno debug option. I haven't managed to get such high precision since I recompiled my kernel. > - test program test_stability_trace.c > - xenomai timer library support implementation support_xenomai.c > > Thanks in advance. You should use pthread_setschedparam instead of sched_setscheduler. -- Gilles Chanteperdrix