On 3/17/20 9:47 AM, Christophe Leroy wrote: > > > 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. > Ah, ok. You are simply using a few interfaces in the hugetlb header files. The huge pages created in your mappings are not PageHuge() pages. -- Mike Kravetz
