Re: Why HZ on i386 is 100 ?

David Mosberger
2002-04-16T16:50:24Z

>>>>> On Tue, 16 Apr 2002 16:27:12 +0000 (UTC), torvalds@transmeta.com (Linus Torvalds) said:

Linus> And I've had some Intel people grumble about it, because it
Linus> apparently means that the timer tick takes anything from 2%
Linus> to an extreme of 10% (!!) of the CPU time under certain
Linus> loads.

I'm not sure I believe this. I have had occasional cases where I
wondered whether the timer tick caused significant overhead, but it
always turned out to be something else. In my measurements,
*user-level* profiling has the 2-10% overhead you're mentioning, but
that's with a signal delivered to user level on each tick.

--david