Re: [patch] CFS scheduler, -v6

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

On Sun, Apr 29, 2007 at 09:16:27AM +0200, Willy Tarreau wrote:
> In fact, what I'd like to see in 2.6.22 is something better for everybody
> and with *no* regression, even if it's not perfect. I had the feeling
> that SD matched that goal right now, except for Mike who has not tested
> recent versions. Don't get me wrong, I still think that CFS is a more
> interesting long-term target. But it may require more time to satisfy
> everyone. At least with one of them in 2.6.22, we won't waste time
> comparing to current mainline.

I think it'd be a good idea to merge scheduler classes before changing
over the policy so future changes to policy have smaller code impact.
Basically, get scheduler classes going with the mainline scheduler.

There are other pieces that can be merged earlier, too, for instance,
the correction to the comment in init/main.c. Directed yields can
probably also go in as nops or -ENOSYS returns if not fully implemented,
though I suspect there shouldn't be much in the way of implementing them.
p->array vs. p->on_rq can be merged early too. Common code for rbtree-
based priority queues can be factored out of cfq, cfs, and hrtimers.
There are extensive /proc/ reporting changes, large chunks of which
could go in before the policy as well.

I'm camping in this weekend, so I'll see what I can eke out.


-- wli