Re: [PATCH] Optimize out pte_chain take three

William Lee Irwin III
2002-07-11T02:28:20Z

On Wed, Jul 10, 2002 at 06:51:02PM -0700, William Lee Irwin III wrote:
> I'm not entirely sure, but I do have ideas of what I think would
> exercise specific (sub)functions of the VM.

I thought of another:

(4) A group of memory dirtying processes dirties memory at a rate
exceeding the I/O bandwidth of the system.

The VM's goal is to do "thrash control" for dirty memory
generation by basically picking a subset of the dirty
memory generators fitting within its I/O budget, letting
them run for a while, and then putting them all to sleep
after that and moving on to a different subset of the
dirty memory generators, and so alternating between them.

The measurable criteria would be foremost the variance in dirtying
rates of the processes over their lifetimes, and secondarily
dirtying throughput. The pass/fail criteria would be the ability
to recognize the situation and stay within the "I/O budget".

Cheers,
Bill