Re: [patch 0/3] [Announcement] Performance Counters for Linux

Arjan van de Ven
2008-12-05T14:59:47Z

On Fri, 05 Dec 2008 00:07:16 -0800 (PST)
David Miller <davem@davemloft.net> wrote:

> These things aren't measuring time, or even just cycles, they
> are measuring things like L2 cache misses, cpu cycles, and
> other similar kinds of events.
>
> So these counters are going to measure all of the damn crap
> assosciated with doing the read() call as well as the real work
> the task does.

as you said before, not if you do the read() from a thread that's
exempt from the profiling.

--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org