On Wed, Jul 02, 2008 at 01:03:27PM +0200, Wolfgang Grandegger wrote: > Wolfgang Grandegger wrote: >> Steven Rostedt wrote: >> There seems to be something in trace_mark() keeping latency low: >> http://lxr.linux.no/linux+v2.6.24.4/include/linux/marker.h#L52 >> I will follow your suggestions. > > I removed all "likely" and "unlikely" macros, but the latencies did not > improve. Then I added > > preempt_disable(); > preempt_enable(); > > at the two locations mentioned above, like trace_mark() does, and disabled > CONFIG_RCU_TRACE. That helped to keep the latencies low, and it did for > 2.6.25.8-rt7 as well. As I see it, adding preemption points seem to prevent > high latencies. Interesting. Perhaps a preempt_enable_no_resched() somewhere that should be preempt_enable()? Thanx, Paul -- 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
