> > Preempt RT do not manage priorities properly for interrupts while RTAI and > > Xenomai do. It is rather simple, execution time to service an interupt > > every > > now and then will delay real time tasks with as much time as they take to > > execute. Then there are SMI which will interrupt anyway. I run control loop > > at micro controller at 40kHz and it works perfect because it allow nested > > interrupts with priority. > > > > umm not true at all > > http://freeby.mesanet.com/h97-g3258-preemt-rt.png > > RTAI is not significantly better on decent modern hardware > > Many PC latency issues are hardware related (DMA, Caching etc) and affect > Preempt-RT, RTAI and Xenomai equally
These times seems really good but the last time I read about Preempt RT they had chosen not to manage interrupt properly. If interrupts are allowed to interrupt real time tasks this time need to be added. In particular period must be longer than interrupt execution time or sometimes dead line will be missed. There are tasks with real time demands in ordinary operating systems also. Like receive buffer for digital communication so it is possible modern hardware have spent some time to get rid of these kind of small problems. Jitter is less important. Delay longer than period is a problem. I expect jitter in all tasks except the highest priority. Nicklas Karlsson ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
