I have a problem that looks like either process scheduling, or buffering, some sort of blocking on a linuxcnc host running 12.04/Xenomai and 2.6.0pre. It does not display this problem on 10.04/RTAI and 2.6.0pre (same base hardware, an intel atom board). The symptom is that when continuously jogging, a DRO showing position on a remote device changes smoothly when talking to 10.04/rtai. On 12.04/xenomai we get a distinct pattern of three updates and a pause, three updates and a pause. The pause is some number of milliseconds long (1/4 second maybe) and distinctly visible. The remote connection is through our web server (Rockhopper) over tcp (websocket) on wired ethernet.
We first thought it was packet buffering or network latency and played with TCP parameters and system buffers but that had no effect. We put timing statements in the web server code at the point were we write the data out and it appears that the whole web server process is being blocked or something. We tried re-nicing the web server but it didn't help. If we run Axis locally while doing this it doesn't display this pause, it moves along smoothly as one would expect. For debugging I thought I might try 12.04 and rtai to see if it was just with the xenomai kernel or if rtai on 12 does it as well. Are there rtai packages available for 12.04 yet? I was going through the email list archive on the new RT stuff but don't see any pointer to packages on rtai specifically... Any thoughts on what we might look at to narrow it down further? -Tom ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
