> We can just detect the deviation in the callback itself: > > u64 now = ktime_get_mono_fast_ns(); > > if (now - __this_cpu_read(nmi_timestamp) < period) > return; > > __this_cpu_write(nmi_timestamp, now); > > It's that simple. It's a simple short term hac^wsolution. But if we had a (hypothetical) system with let's say 10*TSC max you may end up with quite a few false ticks, as in unnecessary interrupts. With 100*TSC it would be really bad. There were systems in the past that ran TSC at a much slower frequency, such as the early AMD Barcelona systems. So the problem may eventually come back if not solved properly. -Andi -- ak@xxxxxxxxxxxxxxx -- Speaking for myself only -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html