[PATCH] mm/hugetlb: Fix build failure with HUGETLB_PAGE but not HUGEBTLBFS

[Christophe Leroy]

Le 17/03/2020 à 17:40, Mike Kravetz a écrit :
> On 3/17/20 1:43 AM, Christophe Leroy wrote:
>>
>>
>> Le 17/03/2020 à 09:25, Baoquan He a écrit :
>>> On 03/17/20 at 08:04am, Christophe Leroy wrote:
>>>> When CONFIG_HUGETLB_PAGE is set but not CONFIG_HUGETLBFS, the
>>>> following build failure is encoutered:
>>>
>>>   From the definition of HUGETLB_PAGE, isn't it relying on HUGETLBFS?
>>> I could misunderstand the def_bool, please correct me if I am wrong.
>>
>> AFAIU, it means that HUGETLBFS rely on HUGETLB_PAGE, by default HUGETLB_PAGE is not selected when HUGETLBFS is not. But it is still possible for an arch to select HUGETLB_PAGE without selecting HUGETLBFS when it uses huge pages for other purpose than hugetlb file system.
>>
> 
> Hi Christophe,
> 
> Do you actually have a use case/example of using hugetlb pages without
> hugetlbfs?  I can understand that there are some use cases which never
> use the filesystem interface.  However, hugetlb support is so intertwined
> with hugetlbfs, I am thinking there would be issues trying to use them
> separately.  I will look into this further.
> 

Hi Mike,

Series https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=164620

And especially patch 39 to 41.

Thanks
Christophe