On Tue, 10 May 2022 16:17:39 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > + > > +static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, > > + unsigned long addr, pte_t *ptep) > > +{ > > + return ptep_get(ptep); > > +} > > + > > +static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, > > + pte_t *ptep, pte_t pte) > > +{ > > +} > > #endif /* CONFIG_HUGETLB_PAGE */ > > > > This blows up nommu (arm allnoconfig): > > In file included from fs/io_uring.c:71: > ./include/linux/hugetlb.h: In function 'huge_ptep_clear_flush': > ./include/linux/hugetlb.h:1100:16: error: implicit declaration of function 'ptep_get' [-Werror=implicit-function-declaration] > 1100 | return ptep_get(ptep); > | ^~~~~~~~ > > > huge_ptep_clear_flush() is only used in CONFIG_NOMMU=n files, so I simply > zapped this change. > Well that wasn't a great success. Doing this instead. It's pretty nasty - something nicer would be nicer please. --- a/include/linux/hugetlb.h~mm-rmap-fix-cont-pte-pmd-size-hugetlb-issue-when-migration-fix +++ a/include/linux/hugetlb.h @@ -1094,6 +1094,7 @@ static inline void set_huge_swap_pte_at( { } +#ifdef CONFIG_MMU static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { @@ -1104,6 +1105,7 @@ static inline void set_huge_pte_at(struc pte_t *ptep, pte_t pte) { } +#endif #endif /* CONFIG_HUGETLB_PAGE */ static inline spinlock_t *huge_pte_lock(struct hstate *h, _