Re: [PATCH RFC] cpu alloc cleanups and implementation improvement

Rusty Russell
2008-11-23T09:33:28Z

On Saturday 22 November 2008 01:19:29 Christoph Lameter wrote:
> On Fri, 21 Nov 2008, Stephen Rothwell wrote:
> > > I would not mind if you would take over from here.
> >
> > So, should I remove the cpu_alloc tree from linux-next?
>
> I think the cpu_alloc branch itself is fine because it only contains the
> allocator and a single use case.

I think the textual conflicts kill us, but yes, they're orthgonal.

> The more invasive stuff is stage2 and the following which is not in next
> yet. The way I envision to go forward is with a gradual transition to the
> new APIs converting dynamic percpu users to use the new percpu operations
> and functionality.

Yes, and this is the real payoff (though your slub tranformation is pretty
sweet too..).

> The whole thing becomes riskier if we directly replace all allocpercpu
> users as proposed by Rusty.
>
> Rusty, are you going to take this on?

Yes, I think I have to. It's always risky to replace an implementation, but
IMHO the current one was always a stopgap.

Sure, the net ones are probably going to have to revert to a boutique old-
style percpu allocator until we have growing per-cpu regions. But Dave's
already suggested something similar.

Thanks,
Rusty.