On Tue, 2012-12-11 at 09:02 -0500, Steven Rostedt wrote: > Currently, what we have is a huge contention on both the pulled CPU rq > lock. We've measured over 500us latencies due to it. This hurts even the > CPU that has the overloaded task, as the contention is on its lock. The 500us latency was one of the max ones I saw, and I believe it was combined with the load balancer going off at the same time as the pulls were happening. I've seen larger latencies with limited function tracing enabled and the load balancer was very involved. As I believe we have users that would very much want this in, and if you are still not sure you like this "feature" I can make it into a SCHED_FEAT() like TTWU_QUEUE. Then you can keep this off and the big boxes can enable them. Maybe enable the feature by default if the box has more than 16 cpus? -- 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
