Re: Scheduler regression: Too frequent timer interrupts(?)

From: Ingo Molnar
Date: Fri Apr 17 2009 - 11:35:57 EST



* Christoph Lameter <cl@xxxxxxxxx> wrote:

> On Fri, 17 Apr 2009, Peter Zijlstra wrote:
>
> > And a random 1us cutoff, is well, random.
>
> Its got to be somewhere.

Sorry, that's not a rational answer that makes any sense.

Peter's point is statistics 101: please show absolute values not an
event distribution cutoff - how much total time do we spend in the
kernel in that workload?

Is the overhead 1%? 2%? 0.5%? And how did it change from 2.6.22
onwards? Did it go up by 0.1%, from 1% to 1.1%? Or did the average
go down by 0.05%, while increasing the spread of events (thus
fooling your cutoff)?

These are very simple, very basic, very straightforward questions -
and no straight answer was forthcoming from you. Are you not
interested in that answer?

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/