Re: dynamic-hz

Andrea Arcangeli
2004-12-12T22:23:18Z

On Sun, Dec 12, 2004 at 05:35:47PM +0100, Pavel Machek wrote:
> It certainly helps with singing capacitors... What is overhead of

;)

> this?

The overhead is a single l1 cacheline in the paths manipulating HZ
(rather than having an immediate value hardcoded in the asm, it reads it
from a memory location not in the icache). Plus there are some
conversion routines in the USER_HZ usages. It's not a measurable
difference.