rb@chroma.med.upenn.edu (Richard J. Bookman) (01/16/89)
Question: Can I run a job with such a priority that it will correctly detect an event every 33milliseconds? (The actual acceptable performance is to miss NO event in 17 seconds enough of the time, i.e., most (>50%) of the 17 second trials should report NO missing events.) Background: I have a 3/260, running 4.0.1, with no other users but with a reasonable collection of daemons. A NICE PC!!!! A frame grabber is sitting in an externable VME box grabbing incoming video from my microscope. I want to count the number of elapsed frames from a START signal. I am (or can be) root. I have no one else to worry about. If need be I can shut down every other process. I do not want to use interrupts (don't ask)... I just want to sit there polling this register. Renice-ing (-20) did not seem to help (at least from within Sunview); I have the impression that something is starting to trip over its own feet as the shelltool starts to behave strangely. Using setpriority(,,-20) and chmod +s did NOT improve things; in fact, it seems to have made them worse. Solutions and kibbitzing will be greatly appreciated! Thanks, Dr. Richard J. Bookman Department of Physiology internet:rb@chroma.med.upenn.edu University of Pennsylvania phone :215-898-9555 Philadelphia, PA., 19104-6085