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

Ingo Molnar
2004-08-19T09:09:16Z

* James Courtier-Dutton <James@superbug.demon.co.uk> 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