On Sat, 2013-04-27 at 10:34 +0200, Stanislav Meduna wrote: > A general question: I am seeing a few recent changes in the tracing > code. Is it generally safe to have at least latency histogram enabled > in the production code, or is it advised not to compile these features > in? I'd like to see the latencies the customer is getting in the real > environment, but if the code is considered as work-in-progress, > it is better to play it safe. Only the wakeup latency tracer does not cause a hit to performance. I recommend irqsoff/preemptoff to not be enabled on production systems. Not for safety reasons, but because they cause a noticeable overhead to the kernel when configured in but not enabled. As for the other tracers, the function tracer is usually fine. But some have said that they see a slight performance decrease when configured in. I haven't seen that, but it really does depend on the hardware. The events should not be an issue to configure in. -- Steve -- 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
