Ok, here's a self standing version. The included README has information on how 
to run it. http://www.infoteam.de/downloads/temp/fme/benchmark.tar.gz

In the meantime I found that the worst-case duration is nearly exactly the 
period that is passed into rt_start_timer.

In the test program, a single non-periodic task is used on both sender and 
receiver (it is only paused when blocked on a rt_dev_recvfrom() call). But I 
guess rtnet employs some periodic tasks whose execution period is dependent on 
the period specified in rt_start_timer !?

Frank


-----Ursprüngliche Nachricht-----
Von: Paolo Mantegazza [mailto:mantega...@aero.polimi.it] 
Gesendet: Montag, 28. September 2009 18:23
An: Frank Meier
Cc: rtnet-users@lists.sourceforge.net
Betreff: Re: [RTnet-users] worst-case duration of send/receive sequence

Frank Meier wrote:
> Hello,
> 
> I wrote a very simple program in order to measure the time needed for a
> sending a fixed size data packet and receiving a 1 byte acknowledge. 
> 
> Basically it's:

No °basically° please. Set up a self standing test.

paolo

> while (..)
> {
>       T1 = rt_get_time_ns();
>       Send();   // 65007 byte packet
>       Recv();  // 1 byte ACK
>       T2 = rt_get_time_ns();
> }
> 
> When looking at the duration T2-T1, I found that the worst-case value
> was always 1000000ns (independent of the number of loop cycles or the
> packet size used).
> 
> Is this a known problem?
> 
> System information:
> x86, Linux 2.6.22, RTAI 3.6cv, rtnet 0.9.9, e1000 driver with Intel
> 82541 NIC, no RTmac
> 
> Best regards,
> Frank
> 
> 
> 
> 
> 
> 
> 
> ------------------------------------------------------------------------------
> Come build with us! The BlackBerry® Developer Conference in SF, CA
> is the only developer event you need to attend this year. Jumpstart your
> developing skills, take BlackBerry mobile applications to market and stay 
> ahead of the curve. Join us from November 9-12, 2009. Register now!
> http://p.sf.net/sfu/devconf
> _______________________________________________
> RTnet-users mailing list
> RTnet-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/rtnet-users
> 



------------------------------------------------------------------------------
Come build with us! The BlackBerry® Developer Conference in SF, CA
is the only developer event you need to attend this year. Jumpstart your
developing skills, take BlackBerry mobile applications to market and stay 
ahead of the curve. Join us from November 9-12, 2009. Register now!
http://p.sf.net/sfu/devconf
_______________________________________________
RTnet-users mailing list
RTnet-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/rtnet-users

Reply via email to