1M hugepage size being registered on Linux

[Michael Ellerman]

victora <victora at linux.vnet.ibm.com> writes:

> Hi Alistair/Jeremy,
>
> I am working on a bug related to 1M hugepage size being registered on 
> Linux (Power 8 Baremetal - Garrison).

Wasn't that caused by a firmware bug?

> I was checking dmesg and it seems that 1M page size is coming from 
> firmware to Linux.
>
> [    0.000000] base_shift=20: shift=20, sllp=0x0130, avpnm=0x00000000, 
> tlbiel=0, penc=2
> [    1.528867] HugeTLB registered 1 MB page size, pre-allocated 0 pages
>
> Should Linux support this page size?

Does it work? :)

The user manual says it's a supported size, but I thought it didn't work
(in hardware) for some reason.

cheers