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| author | Johannes Weiner <hannes@cmpxchg.org> | 2011-01-13 15:47:02 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 17:32:44 -0800 |
| commit | 0ca1634d4143c3579273ca53b993df19f5c98e92 (patch) | |
| tree | d566a582357a9e1528d1783566bfda4375c7e566 | |
| parent | f2d6bfe9ff0acec30b713614260e78b03d20e909 (diff) | |
| download | lwn-0ca1634d4143c3579273ca53b993df19f5c98e92.tar.gz lwn-0ca1634d4143c3579273ca53b993df19f5c98e92.zip | |
thp: mincore transparent hugepage support
Handle transparent huge page pmd entries natively instead of splitting
them into subpages.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/huge_mm.h | 3 | ||||
| -rw-r--r-- | mm/huge_memory.c | 25 | ||||
| -rw-r--r-- | mm/mincore.c | 8 |
3 files changed, 35 insertions, 1 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 43a694ef8904..25125fb6acf7 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -19,6 +19,9 @@ extern struct page *follow_trans_huge_pmd(struct mm_struct *mm, extern int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd); +extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, + unsigned long addr, unsigned long end, + unsigned char *vec); enum transparent_hugepage_flag { TRANSPARENT_HUGEPAGE_FLAG, diff --git a/mm/huge_memory.c b/mm/huge_memory.c index ae2bf08b1099..37e89a32a0b1 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -923,6 +923,31 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, return ret; } +int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, + unsigned long addr, unsigned long end, + unsigned char *vec) +{ + int ret = 0; + + spin_lock(&vma->vm_mm->page_table_lock); + if (likely(pmd_trans_huge(*pmd))) { + ret = !pmd_trans_splitting(*pmd); + spin_unlock(&vma->vm_mm->page_table_lock); + if (unlikely(!ret)) + wait_split_huge_page(vma->anon_vma, pmd); + else { + /* + * All logical pages in the range are present + * if backed by a huge page. + */ + memset(vec, 1, (end - addr) >> PAGE_SHIFT); + } + } else + spin_unlock(&vma->vm_mm->page_table_lock); + + return ret; +} + pmd_t *page_check_address_pmd(struct page *page, struct mm_struct *mm, unsigned long address, diff --git a/mm/mincore.c b/mm/mincore.c index 9959bb41570e..a4e6b9d75c76 100644 --- a/mm/mincore.c +++ b/mm/mincore.c @@ -154,7 +154,13 @@ static void mincore_pmd_range(struct vm_area_struct *vma, pud_t *pud, pmd = pmd_offset(pud, addr); do { next = pmd_addr_end(addr, end); - split_huge_page_pmd(vma->vm_mm, pmd); + if (pmd_trans_huge(*pmd)) { + if (mincore_huge_pmd(vma, pmd, addr, next, vec)) { + vec += (next - addr) >> PAGE_SHIFT; + continue; + } + /* fall through */ + } if (pmd_none_or_clear_bad(pmd)) mincore_unmapped_range(vma, addr, next, vec); else |