Re: [PATCH 7/7] Simple Performance Counters: SLUB instrumentation

[Christoph Lameter]

On Fri, 17 Aug 2007, Mathieu Desnoyers wrote:

> Why do you printk inside the timing period ? Filling the printk buffers
> or outputting on things such as serial console could really hurt your
> results.

It was easier to code?

> I hope you run your system with idle=poll and without frequency scaling
> at all, because otherwise your cycle count would be completely off on
> many AMD and Intel CPUs. You can have a look at this (very rough)
> document on the topic: 

The cpu will definitely not be idle during these measurements and no 
frequency scaling is active.
-
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/