On Wed, Mar 26, 2008 at 7:41 PM, Hubert Talbot <[EMAIL PROTECTED]> wrote: > Hi, > > 800 MHz x86 system. > > How can "lat max" vary to consider we have a reliable realtime system ? > > If results are around 40 usec, is it normal that some values are ~75 or ~175 > (especially when two other applications send/receive interrupts) ?
800 MHz is rather slow, so 75 may be normal (albeit rather high), but 175 is too much. You probably have a problem with SMIs... Also normal high peaks usually happen under load. SMI peaks happen even on an idle system. > > Does "lat max" depend on processor frequency ? I think it rather depends on processor class, as a rule of thumb, you will probably get much lower latencies on a core 2 duo than on, say, a pentium 2. > > Does interrupt reception (rt_intr_wait) depend on processor frequency ? The latency test uses the timer interrupt, you control the sampling period with the -p argument. -- Gilles _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
