From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4C6CE4E0.1000609@domain.hid> Date: Thu, 19 Aug 2010 10:01:36 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <4C6C019D.1040406@domain.hid> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] Timing calculation List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Prakash A S Cc: xenomai@xenomai.org Prakash A S wrote: > On Wed, Aug 18, 2010 at 9:21 PM, Gilles Chanteperdrix < >> We still receive HTML. >> > > May be because of simply copy and pasted the old content in the last thread. > > How about the scenario now?. Nope. Still multipart/alternative with HTML. > > >>> Obviously I should improve my C language skills. >>> >>> I am using linux kernel 2.6.30.8 on Ubuntu 8.04, >>> Adeos-ipipe-2.6.30.8-x86-2.4-09.patch and Xenomai-2.5.3 >> What about the kernel configuration and self-contained test exhibiting >> the behaviour you do not understand? >> > > My .config file is here, http://pastebin.ca/1919917 This .config is wrong: it has ACPI disabled. > I tested and understand few test cases below. > switchtest : I am using Intel Dual core processor. ~5731 context switches > happening in a second > cyclictest : Tested with 10 threads. Maximum timer latency is 38us and > minimum is 1us > clocktest : Simply prints the time offset, drift value and wraps compare > with normal linux's gettimeofday(). Not much understand from this test. > latency : user mode latency test provides maximum latency time is 15us. > latency : kernel mode latency test provides maximum latency time is 3.6 us > latency : timer mode latency test provides maximum latency time is 3 us So, timing works correctly. If there was something wrong with time keeping, you would have seen latency and switchtest drifting, and printing infinitely increasing or decreasing latencies. > > Not much understand about the clocktest. > More helpful if we have any documentations for the all tests rather than how > to use the tests. The fact that ACPI must be enabled is documented, though you disabled it, which proves that you do not read the documentation. What I would like you is to do is to write a self-contained as simple as possible test which exhibits the behaviour you find suspicious, and publish it here so that I can try and reproduce this behaviour. -- Gilles.