Re: [patch] Real-Time Preemption, -RT-2.6.12-V0.7.49-00

From: Esben Nielsen
Date: Wed Jun 22 2005 - 03:57:26 EST

On Wed, 22 Jun 2005, Ingo Molnar wrote:

> * Esben Nielsen <simlo@xxxxxxxxxx> wrote:
> > Yep, just as I pressed sent before I saw the following:
> ok, i'll have to look at the latency trace of this.
> > threshold violated: 28.0% (273usec)
> btw., are you sure this happened with latency timing/tracing disabled?
> (the printks will disturb the rtc_wakeup test).
But I have been running the same load with latence timing on and have not
seen traces of more than ~50us.

I do have problems with calibration of the clock in both rtc_wakeup and
realfeel2 due to frequency scaling, but it looks like if I have a cpu-hog
running it settles itself on the 697MHz as it should. But could this
frequency scaling lead to bad readings? If it for some reason scales down
the clock during a test it ought to give lower clock counts than the real
ones, not higher...

> 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
Please read the FAQ at