Re: [PATCH] x86-64: fix 1:1 mapping init (hotplug case)

[Ingo Molnar <mingo@elte.hu>]

* Jan Beulich <jbeulich@novell.com> wrote:

> While I don't have a hotplug capable system at hand, I think two issues need
> fixing:
> - pud_phys (in kernel_physical_ampping_init()) would remain uninitialized in
>   the after_bootmem case
> - the locking done just around phys_pmd_{init,update}() would leave out pgd
>   updates, and it was needlessly covering code portions that do allocations
>   (perhaps using a more friendly gfp value in alloc_low_page() would then be
>   possible)

applied to tip/x86/urgent. Some sort of memory hotplug simulation debug 
code would be nice ... [bonus points for making it run automatically 
during bootup, as part of the kernel init code]

it wouldnt even be all that expensive to test: we'd parts of RAM as 
to-be-hotplugged, we'd boot in and then hot-add those ranges. It's not 
full unrestricted RAM in the classic sense, but for most practical 
purposes it would be that.

	Ingo