1M hugepage size being registered on Linux

[Michal Suchánek]

On Tue, 20 Jun 2017 10:47:47 -0300
victora <victora at linux.vnet.ibm.com> wrote:

> Hi Alistair/Jeremy,
> 
> I am working on a bug related to 1M hugepage size being registered on 
> Linux (Power 8 Baremetal - Garrison).
> 
> 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? As afar as I know, this was an 
> unsupported page size in the past isn't it? If this should be
> supported now, is there any specific reason for that?

Hello,

a525108cf1cc powerpc/mm/hugetlb: Filter out hugepage size not supported
by page table layout

Should reject unsupported huge page sizes, right?

Thanks

Michal