* [merged] mm-page_vma_mappedc-explicitly-compare-pfn-for-normal-hugetlbfs-and-thp-page.patch removed from -mm tree
@ 2020-01-31 23:18 akpm
0 siblings, 0 replies; only message in thread
From: akpm @ 2020-01-31 23:18 UTC (permalink / raw)
To: kirill.shutemov, lixinhai.lxh, mhocko, mike.kravetz, mm-commits
The patch titled
Subject: mm/page_vma_mapped.c: explicitly compare pfn for normal, hugetlbfs and THP page
has been removed from the -mm tree. Its filename was
mm-page_vma_mappedc-explicitly-compare-pfn-for-normal-hugetlbfs-and-thp-page.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Li Xinhai <lixinhai.lxh@gmail.com>
Subject: 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/1578737885-8890-1-git-send-email-lixinhai.lxh@gmail.com
Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/page_vma_mapped.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
--- a/mm/page_vma_mapped.c~mm-page_vma_mappedc-explicitly-compare-pfn-for-normal-hugetlbfs-and-thp-page
+++ a/mm/page_vma_mapped.c
@@ -52,12 +52,16 @@ static bool map_pte(struct page_vma_mapp
return true;
}
-static inline bool pfn_in_hpage(struct page *hpage, unsigned long pfn)
+static inline bool pfn_is_match(struct page *page, unsigned long pfn)
{
- unsigned long hpage_pfn = page_to_pfn(hpage);
+ unsigned long page_pfn = page_to_pfn(page);
+
+ /* normal page and hugetlbfs page */
+ if (!PageTransCompound(page) || PageHuge(page))
+ return page_pfn == pfn;
/* THP can be referenced by any subpage */
- return pfn >= hpage_pfn && pfn - hpage_pfn < hpage_nr_pages(hpage);
+ return pfn >= page_pfn && pfn - page_pfn < hpage_nr_pages(page);
}
/**
@@ -108,7 +112,7 @@ static bool check_pte(struct page_vma_ma
pfn = pte_pfn(*pvmw->pte);
}
- return pfn_in_hpage(pvmw->page, pfn);
+ return pfn_is_match(pvmw->page, pfn);
}
/**
_
Patches currently in -mm which might be from lixinhai.lxh@gmail.com are
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2020-01-31 23:18 [merged] mm-page_vma_mappedc-explicitly-compare-pfn-for-normal-hugetlbfs-and-thp-page.patch removed from -mm tree akpm
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