Hi, > Thank you for this clarification. This really made me think. In > mainline kernel, my interrupt will not be affected by other processes. > But, it can be affected by other interrupts in the system, right? So, > I still gain something from rt patch where I can scale down the > priority of other interrupts so that they don't come in the way of my > 1 ms interrupt. Yes this is correct... > Now, if I got it correct, what I will have to see is whether this > advantage outweighs the disadvantage of context switching delays. A > quick search showed me http://choices.cs.uiuc.edu/ExpCS07.pdf. In page > 25 they have listed time for context switches and interrupts. Those > figures are rather dismal (~few milli seconds). Can someone familiar > with ARM here tell me whether these numbers can be trusted? From the > rt wiki I see that, on ARM, worst case latency is less than 300us. I > will anyway repeat the tests that we did so far and will post the > results again. I did such messures in my diploma work, its written in german but you should be able to read the figures (the messures are done on an arm cpu): http://www.agner.ch/linuxrealtime/Linux-Realtime-Faehigkeiten.pdf PDF Page 47 and following are interessting. You can see the "Durchschnittslatenzzeiten" (average latencies) rt compared with mainline Bye Stefan -- 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
