Re: dynamic-hz

Andrea Arcangeli
2004-12-13T22:26:45Z

On Mon, Dec 13, 2004 at 12:56:29PM -0800, john stultz wrote:
> Interesting patch, I know some folks have been asking about HZ=10k
> recently, so this could help.

Yes, they only need to pass HZ=10000 to the boot command line to make it
work with 2.4.

> The only bit that worries me a bit is the change from HZ->USER_HZ for
> internal calculations. In my mind, USER_HZ should only be used for
> converting internal system ticks to userspace-visible ticks. Changing
> drivers to think about things in user-ticks confuses things a bit since
> suddenly some kernel code is thinking in user-ticks and others in
> system-ticks. It just muddles things a bit.

I tried to make the smallest possible change to make the thing work,
even if that sometime meant to think in user hz. The user_to_kernel_hz
helper function converts back into kernel hz.