Messages in this thread | | | Date | Tue, 20 Jun 2023 19:54:38 +0200 | Subject | Re: [PATCH v2 3/8] mm/hugetlb: Add page_mask for hugetlb_follow_page_mask() | From | David Hildenbrand <> |
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On 20.06.23 18:28, Peter Xu wrote: > On Tue, Jun 20, 2023 at 05:23:09PM +0200, David Hildenbrand wrote: >> On 20.06.23 01:10, Peter Xu wrote: >>> follow_page() doesn't need it, but we'll start to need it when unifying gup >>> for hugetlb. >>> >>> Signed-off-by: Peter Xu <peterx@redhat.com> >>> --- >>> include/linux/hugetlb.h | 8 +++++--- >>> mm/gup.c | 3 ++- >>> mm/hugetlb.c | 5 ++++- >>> 3 files changed, 11 insertions(+), 5 deletions(-) >>> >>> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h >>> index beb7c63d2871..2e2d89e79d6c 100644 >>> --- a/include/linux/hugetlb.h >>> +++ b/include/linux/hugetlb.h >>> @@ -131,7 +131,8 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, >>> int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, >>> struct vm_area_struct *, struct vm_area_struct *); >>> struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, >>> - unsigned long address, unsigned int flags); >>> + unsigned long address, unsigned int flags, >>> + unsigned int *page_mask); >>> long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *, >>> struct page **, unsigned long *, unsigned long *, >>> long, unsigned int, int *); >>> @@ -297,8 +298,9 @@ static inline void adjust_range_if_pmd_sharing_possible( >>> { >>> } >>> -static inline struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, >>> - unsigned long address, unsigned int flags) >>> +static inline struct page *hugetlb_follow_page_mask( >>> + struct vm_area_struct *vma, unsigned long address, unsigned int flags, >>> + unsigned int *page_mask) >>> { >>> BUILD_BUG(); /* should never be compiled in if !CONFIG_HUGETLB_PAGE*/ >>> } >>> diff --git a/mm/gup.c b/mm/gup.c >>> index abcd841d94b7..9fc9271cba8d 100644 >>> --- a/mm/gup.c >>> +++ b/mm/gup.c >>> @@ -780,7 +780,8 @@ static struct page *follow_page_mask(struct vm_area_struct *vma, >>> * Ordinary GUP uses follow_hugetlb_page for hugetlb processing. >>> */ >>> if (is_vm_hugetlb_page(vma)) >>> - return hugetlb_follow_page_mask(vma, address, flags); >>> + return hugetlb_follow_page_mask(vma, address, flags, >>> + &ctx->page_mask); >>> pgd = pgd_offset(mm, address); >>> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >>> index 9a6918c4250a..fbf6a09c0ec4 100644 >>> --- a/mm/hugetlb.c >>> +++ b/mm/hugetlb.c >>> @@ -6454,7 +6454,8 @@ static inline bool __follow_hugetlb_must_fault(struct vm_area_struct *vma, >>> } >>> struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, >>> - unsigned long address, unsigned int flags) >>> + unsigned long address, unsigned int flags, >>> + unsigned int *page_mask) >>> { >>> struct hstate *h = hstate_vma(vma); >>> struct mm_struct *mm = vma->vm_mm; >>> @@ -6499,6 +6500,8 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, >>> page = NULL; >>> goto out; >>> } >>> + >>> + *page_mask = ~huge_page_mask(h) >> PAGE_SHIFT; >> >> As discussed, can be simplified. But can be done on top (or not at all, but >> it is confusing code). > > Since we decided to make this prettier.. At last I decided to go with this: > > *page_mask = (1U << huge_page_order(h)) - 1; > > The previous suggestion of PHYS_PFN() will do two shifts over PAGE_SIZE > (the other one in huge_page_size()) which might be unnecessary, also, PHYS_ > can be slightly misleading too as prefix. > >> >> Reviewed-by: David Hildenbrand <david@redhat.com> > > I'll take this with above change, please shoot if not applicable. Thanks, >
Perfectly fine :)
-- Cheers,
David / dhildenb
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