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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 /include | |
| 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 'include')
| -rw-r--r-- | include/linux/huge_mm.h | 5 | ||||
| -rw-r--r-- | include/linux/mm.h | 7 |
2 files changed, 10 insertions, 2 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 8ca35a131904..d39fa60bd6bf 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -104,7 +104,8 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, #define split_huge_pmd(__vma, __pmd, __address) \ do { \ pmd_t *____pmd = (__pmd); \ - if (pmd_trans_huge(*____pmd)) \ + if (pmd_trans_huge(*____pmd) \ + || pmd_devmap(*____pmd)) \ __split_huge_pmd(__vma, __pmd, __address); \ } while (0) @@ -124,7 +125,7 @@ static inline bool pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma, spinlock_t **ptl) { VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma); - if (pmd_trans_huge(*pmd)) + if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) return __pmd_trans_huge_lock(pmd, vma, ptl); else return false; diff --git a/include/linux/mm.h b/include/linux/mm.h index a9902152449f..cd123272d28d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -329,6 +329,13 @@ struct inode; #define page_private(page) ((page)->private) #define set_page_private(page, v) ((page)->private = (v)) +#if !defined(__HAVE_ARCH_PTE_DEVMAP) || !defined(CONFIG_TRANSPARENT_HUGEPAGE) +static inline int pmd_devmap(pmd_t pmd) +{ + return 0; +} +#endif + /* * FIXME: take this include out, include page-flags.h in * files which need it (119 of them) |