Hello, I am fairly new to RT Preempt, but now to realtime embedded systems. I am trying to get EMC2 running on RT Preempt, and I was given some old patches on the mailing list which miracously worked. From here I am trying to get a complete system built from scratch with 'latest' RT Preempt and EMC2. My question is how to go about finding out what causes latencies and jitter, I have no problem to create some code to benchmark latencies or jitter, but how do I find out where the kernel is spending it's time ? Any hints would be much appreciated, since i really don't have a clue on how to go about this. I was thinking that if I could create a realtime task to test for a specific thing, I really would like a log of what the kernal was doing right before this. The only way I can think of is creating a module with a ring buffer ( spill over ), and tracing the scheduler or interrupt handler .... ( by hackíng some code to specifically do this ), this would only add a small overhead AFAIK. Any idea's anyone ? or hints ? It seem's like just the thing that already might have a solution in place, so I figured I should not reinvent the wheel. / best regards, Lars Segerlund. -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
