On Wed, 2 Jul 2008, Wolfgang Grandegger wrote: > > 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. This to me sounds like we have preempt_enable_noresched someplace that shouldn't. In otherwords, we enabled preemption without checking if preemption is needed, which is a serious bug in -rt. -- 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
