On Thu, 2015-06-11 at 10:34 +0200, Thomas Gleixner wrote: > Can you try the following, please? > > Enable function tracer and hrtimer events manually. Then watch the irq > count on cpu3. If it stalls or becomes slow, then stop the trace with > > echo 0 >/sys/kernel/debug/tracing/tracing_on > > If the overhead of the function tracer hides the problem, then try just > with hrtimer, sched_switch and irq events.
Yeah, function tracer hides it. After some fiddling with buffer size to be able to ever see a tick, I finally have a trace trimmed with a tick on each end, 175ms gap between them. It's still 1.5 after xz, sending off list. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/