Iratxo, On Thu, 18 Jun 2009, Iratxo Pichel Ortiz wrote: > Having read the three of them, regardless of the last process before the > "NOHZ...", there is always a call to the FPE emulator. I am going to do some > tests changing the FPE emulator, in case it helps. No, what happens is that the -RT starvation protector kicks in. That's a mechanism which checks whether the CPU is monopolized by rt tasks for longer than 950ms. It then blocks execution of rt tasks for 50ms. The silly thing is that it goes idle, but that's a different problem. It's default on and can be disabled via: echo 0 > /proc/sys/kernel/rt_runtime_us Sorry that I did not notice that earlier, but when that triggers, then something is really wrong. There should never be a situation where -rt tasks (neither irq threads nor softirqs) should monopolize the CPU. Thanks, tglx -- 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
