Re: [PATCH v3 2/2] powerpc/mm/hugetlb: Add support for 1G huge pages

[Michael Ellerman]

"Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> writes:

> On Thursday 18 May 2017 10:51 AM, Michael Ellerman wrote:
>> "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> writes:
>> 
>>> POWER9 supports hugepages of size 2M and 1G in radix MMU mode. This patch
>>> enables the usage of 1G page size for hugetlbfs. This also update the helper
>>> such we can do 1G page allocation at runtime.
>>>
>>> We still don't enable 1G page size on DD1 version. This is to avoid doing
>>> workaround mentioned in commit: 6d3a0379ebdc8 (powerpc/mm: Add
>>> radix__tlb_flush_pte_p9_dd1()
>>>
>>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
>>> ---
>>>   arch/powerpc/include/asm/book3s/64/hugetlb.h | 10 ++++++++++
>>>   arch/powerpc/mm/hugetlbpage.c                |  7 +++++--
>>>   arch/powerpc/platforms/Kconfig.cputype       |  1 +
>>>   3 files changed, 16 insertions(+), 2 deletions(-)
>> 
>> I think this patch is OK, but it's very confusing because it doesn't
>> mention that it's only talking about *generic* gigantic page support.
>
> What you mean by generic gigantic page ? what is supported here is the 
> gigantic page with size 1G alone ?

What about 16G pages on pseries.

And all the other gigantic page sizes that Book3E supports?

cheers