Dear RT community, I have a question regarding the configuration of real-time tasks in PREEMPT _RT kernels > 2.6.33. Up to now, I only have experience with 2.6.33-rt. I use the openPOWERLINK[1] real-time ethernet stack, and have it running on an x86-box with Ubuntu 13.04. I try to use it with two different kernel versions: * 2.6.33.7.2-rt30 * 3.2.48-rt69 When I use kernel version 2.6.33, I get very good results (jitter of ethernet frames on the network < +/-10us). But when I use kernel version 3.2, the results are much worse. The jitter on the network increases up to +/-50us. In my configuration, the openPOWERLINK stack consists of a kernel module (data link layer) and a user space application. I know that in 2.6.33 there were splitted softirqs, and that it was possible to configure each thread with its own priority. What are the steps that need to be done in 3.x to achieve similar results as in 2.6.33? kind regards, Wolfgang Wallner [1] http://sourceforge.net/projects/openpowerlink/ PS: Running cyclictest (e.g. sudo cyclictest -p 99 -n -i 500) on both kernels shows very similar results (avg latency: 15us, max latency 35us). -- 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
