Re: Page Colouring (was: 2.6.0 Huge pages not working as expected)

[William Lee Irwin III <wli@holomorphy.com>]

Linus Torvalds <torvalds@osdl.org> writes:
>> Basically: prove me wrong. People have tried before. They have failed. 
>> Maybe you'll succeed. I doubt it, but hey, I'm not stopping you.

On Sat, Dec 27, 2003 at 04:31:22PM -0700, Eric W. Biederman wrote:
> For anyone taking you up on this I'd like to suggest two possible
> directions.
> 1) Increasing PAGE_SIZE in the kernel.
> 2) Creating zones for the different colors.  Zones were not
>    implemented last time, this was tried.
> Both of those should be minimal impact to the complexity
> of the current kernel. 
> I don't know where we will wind up but the performance variation's
> caused by cache conflicts in today's applications are real, and easily
> measurable.  Giving the growing increase in performance difference
> between CPUs and memory Amdahl's Law shows this will only grow
> so I think this is worth looking at.

Increasing PAGE_SIZE in the kernel either (a) breaks ABI or (b) is
nontrivial. I suppose I should try some of the page coloring benchmarks
on pgcl (which preserves ABI).

-- wli