mm/page_vma_mapped.c: explicitly compare pfn for normal, hugetlbfs and THP page

When check_pte, pfn of normal, hugetlbfs and THP page need be compared.
The current implementation apply comparison as

- normal 4K page: page_pfn <= pfn < page_pfn + 1
- hugetlbfs page:  page_pfn <= pfn < page_pfn + HPAGE_PMD_NR
- THP page: page_pfn <= pfn < page_pfn + HPAGE_PMD_NR

in pfn_in_hpage.  For hugetlbfs page, it should be page_pfn == pfn

Now, change pfn_in_hpage to pfn_is_match to highlight that comparison is
not only for THP and explicitly compare for these cases.

No impact upon current behavior, just make the code clear.  I think it
is important to make the code clear - comparing hugetlbfs page in range
page_pfn <= pfn < page_pfn + HPAGE_PMD_NR is confusing.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Li Xinhai <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Acked-by: Mike Kravetz <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions