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| author | Dan Williams <dan.j.williams@intel.com> | 2016-01-16 03:56:52 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-16 04:56:32 +0300 |
| commit | 5c7fb56e5e3f7035dd798a8e1adee639f87043e5 (patch) | |
| tree | e3419de32c4b42c918267a50120549cbec2ed63f /arch/x86 | |
| parent | 5c2c2587b13235bf8b5c9027589f22eff68bdf49 (diff) | |
| download | linux-5c7fb56e5e3f7035dd798a8e1adee639f87043e5.tar.xz | |
mm, dax: dax-pmd vs thp-pmd vs hugetlbfs-pmd
A dax-huge-page mapping while it uses some thp helpers is ultimately not
a transparent huge page. The distinction is especially important in the
get_user_pages() path. pmd_devmap() is used to distinguish dax-pmds
from pmd_huge() and pmd_trans_huge() which have slightly different
semantics.
Explicitly mark the pmd_trans_huge() helpers that dax needs by adding
pmd_devmap() checks.
[kirill.shutemov@linux.intel.com: fix regression in handling mlocked pages in __split_huge_pmd()]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/pgtable.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 6585a8b10fea..6a0ad82c8d0f 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -164,13 +164,20 @@ static inline int pmd_large(pmd_t pte) #ifdef CONFIG_TRANSPARENT_HUGEPAGE static inline int pmd_trans_huge(pmd_t pmd) { - return pmd_val(pmd) & _PAGE_PSE; + return (pmd_val(pmd) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE; } static inline int has_transparent_hugepage(void) { return cpu_has_pse; } + +#ifdef __HAVE_ARCH_PTE_DEVMAP +static inline int pmd_devmap(pmd_t pmd) +{ + return !!(pmd_val(pmd) & _PAGE_DEVMAP); +} +#endif #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ static inline pte_t pte_set_flags(pte_t pte, pteval_t set) |