Re: [patch] Latency Tracer, voluntary-preempt-2.6.8-rc4-O6

[Ingo Molnar]

* James Courtier-Dutton <James@xxxxxxxxxxxxxxxxxxxx> wrote:

> I have found a new problem though:
> 
> # cat latency_trace
> preemption latency trace v1.0
> -----------------------------
>  latency: 1883455195 us, entries: 1 (1)
>  process: ksoftirqd/1/5, uid: 0
>  nice: -10, policy: 0, rt_priority: 0
> =======>
>  0.000ms (+0.000ms): cond_resched_softirq (___do_softirq)
> 
> That looks bad to me. The user did not notice any latency, but 1883
> seconds seems like a high latency to me!

yeah, it doesnt look healthy. This could be some sort of tracing
underflow - what is the 'grep MHz /proc/cpuinfo' value of your box?

Also, could you try the -P4 patch, it has a more robust timestamping
mechanism.

	Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/