CONFIG_PS3_USE_LPAR_ADDR dramically increases boot time

[Arnd Bergmann]

On Monday 18 June 2007, Jimi Xenidis wrote:
> 
> The following change set:
>    http://git.kernel.org/?p=linux/kernel/git/paulus/ 
> powerpc.git;a=commit;h=261efc3f178c8c5b55d76208aee1f39ce247f723
> 
> setting CONFIG_PS3_USE_LPAR_ADDR (which is the default for PS3)  
> changes increases MAX_PHYSADDR_BITS  from 44 to 47 which makes the  
> array 8 time bigger and takes way longer for sparse_init() to run on  
> simulator.
> 
> Is this really the right approach?
> Cell is actually 42 so could not the special address space be 43 or 44?

Unfortunately, the hypervisor chooses the addresses where things get
mapped, and since they are guest-real, there is no hard limit where
the hypervisor puts them, like the 42 bit limit on bare metal.

I guess this will improve if we get virt_mem_map support on powerpc,
but I'm not sure if that's currently being worked on.

	Arnd <><