Hi all, I'm trying the realtime-preempt patch-2.6.18-rt6 on lh7a400 arm system with little success. In a test program I try 5 ms timeout with select() but get 20 ms avg or 26 ms max. When the framebuffer scrolls, the max delay goes up to 59 ms. With a vanilla kernel I get 10 ms (because of tick resolution?), 11 ms and 39 ms.
My question is, is the realtime-preempt patch supposed to work on arm architecture and/or without high resolution timer (which lh7a40x seems to lack) at all or should I just try to be more clever. Relevant code: ==== prio.sched_priority = 99; if (sched_setscheduler(0, SCHED_RR, &prio) < 0) ... if (mlockall(MCL_CURRENT | MCL_FUTURE) < 0) ... while (1) { t = raw_timer(); tv.tv_usec = 5000; tv.tv_sec = 0; select(0, 0, 0, 0, &tv); t = raw_timer() - t; if (max_t < t) max_t = t; if (min_t > t) min_t = t; avg_t += t; ++n; if (n < 100) continue; printf("%i revs; min: %i max: %i avg: %i\n", n, min_t, max_t, (avg_t + n / 2) / n); ==== Relevant config: PREEMPT_RT, PREEMPT_SOFTIRQS, PREEMPT_HARDIRQS I didnt' enable HIGH_RES_TIMERS because lh7a40x seems not to support it. -- tike ____________________________________________________________________________________ Cheap talk? Check out Yahoo! Messenger's low PC-to-Phone call rates. http://voice.yahoo.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/