powerpc/pseries: Use H_CLEAR_HPT to clear MMU hash table during kexec

[Michael Ellerman]

On Sat, 2016-01-10 at 10:41:56 UTC, Anton Blanchard wrote:
> From: Anton Blanchard <anton at samba.org>
> 
> An hcall was recently added that does exactly what we need
> during kexec - it clears the entire MMU hash table, ignoring any
> VRMA mappings.
> 
> Try it and fall back to the old method if we get a failure.
> 
> On a POWER8 box with 5TB of memory, this reduces the time it takes to
> kexec a new kernel from from 4 minutes to 1 minute.
> 
> Signed-off-by: Anton Blanchard <anton at samba.org>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/5246adec59458b5d325b8e1462ea9e

cheers