From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <45533755.1000201@domain.hid> Date: Thu, 09 Nov 2006 15:12:37 +0100 From: Wolfgang Grandegger MIME-Version: 1.0 Subject: Re: [Xenomai-help] Strange results with latency test References: <20061109133632.GA4205@domain.hid> In-Reply-To: <20061109133632.GA4205@domain.hid> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xenomai@xenomai.org Matthias Fechner wrote: > Hi, > > I tested today Xenomai on my AMD64 (32-bit mode) with the latency > program from the testsuite and I got for lat min negative values. > > Can my computer predict the future? :) Of course, the timer is programmed a bit in advance taking into account some average latency, like code run time, HW latencies, etc. It is system dependent. > How can I interpret these values? > > 100 us > == Test mode: periodic user-mode task > == All results in microseconds > warming up... > RTT| 00:00:01 (periodic user-mode task, 100 us period, priority 99) > RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat worst > RTD| -1.337| -0.958| 0.970| 0| -1.337| 0.970 > RTD| -1.290| -0.907| 1.959| 0| -1.337| 1.959 > ... > RTD| -1.406| -0.923| 1.884| 0| -1.468| 4.358 > ---|------------|------------|------------|--------|------------------------- > RTS| -1.468| -0.922| 4.358| 0| 00:00:34/00:00:34 Add the value listed by 'cat /proc/xenomai/latency` to the above figures or set the latency to "1 ns" with 'echo "1" > /proc/xenomai/latency'. Wolfgang.