On Sat, 2011-05-21 at 18:44 -0600, Peter W. Morreale wrote: > Do you use any pthread* primitives involving scheduling? I'm not quite sure what you mean by scheduling functions... I only use the basic pthread_mutex_* and pthread_cond_* functions. > How do you start your process? How many threads? What else is on the > machine? The main thread starts several threads with pthread_create. I have a barrier which uses pthread_mutex's and pthead_cond's to synchronize the threads. This is where the delays happen. I observed these latencies both on my own laptop (loads of stuff running in the background) and on multi-core servers on which I was alone. I should probably note that I also use OpenMP for some simple parallelization as well. Eg. after releasing the threads and waiting for them all to return to the barrier, some things are computed with OpenMP (OMP_WAIT_POLICY=PASSIVE). The kernels on which I have seen this are the Ubuntu -generic kernels 2.6.31--2.3.35. I have also tried running the simulations on a Ubuntu 2.6.31-11-rt kernel. This, however, caused the whole simulation to run twice as slow, even when only using one single thread (on a 6-core machine). Please do let me know if you need any more specific information! Cheers, Pedro -- 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
