Kernel configuration options

[Jonathan Corbet]

I can't speak for the OLPC kernel folks, but here's a few thoughts:

> First off I noticed CONFIG_NO_HZ=y and CONFIG_HZ=100; is this a quirk of 
> the kernel's general configuration?  As I understand, these options 
> should be mutually exclusive because CONFIG_HZ is a parameter of a 
> scheduler using a different methodology than CONFIG_NO_HZ...

In the current dyntick scheme the regular clock interrupt still happens
when the processor is busy - it's only disabled when things go idle.  So
you still need to set HZ to something.  It also sets the resolution of
much of the timekeeping within the kernel.

> Another thing is I noticed CONFIG_SLAB=y, but the SLUB allocator is 
> supposed to be a faster generic replacement for SLAB.[1]  Is there a 
> reason the XO doesn't use it?

I don't know why that decision was made, but SLUB is still new and still
getting a few things shaken out of it.  Using slab for the
currently-shipped system makes sense to me.

jon