Re: SMP BUG

[Andrew Morton <akpm@osdl.org>]

Russell King <rmk+lkml@arm.linux.org.uk> wrote:
>
> > So I think it's sanest to say that the arch shalt initialise cpu_possible_map
> > in setup_arch().
> 
> Is that the only thing which needs to be initialised early for SMP, or
> are there other changes with early SMP init looming?

Well, I'm not aware of anything - just the patch "percpu data changes" I
sent to linux-arch the other day, which is related to this issue.

The whole early bootup what-the-arch-should-do-when protocol is rather a
mess, so I'm sure other things will need changing.

> The reason I ask is that the cleanest solution for ARM would be to
> introduce yet another initialisation function for MP platforms to
> implement, which setup_arch() will call after the initial page tables
> have been setup.  Hence, I'm wondering if the platform specific parts
> could be simplified by moving more stuff earlier.

That sounds sane.  Perhaps make it a generic setup_arch_platform() whose
mandate is "do whatever needs to be done for setup_arch()".