diff options
| author | Johannes Weiner <hannes@cmpxchg.org> | 2011-01-13 15:47:04 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 17:32:44 -0800 |
| commit | cd7548ab360c462118568eebb8c6da3bc303b02e (patch) | |
| tree | 44d145e6139c8753659ee773ae35810dc3d92d0b /mm/mprotect.c | |
| parent | b36f5b0710e9e3b92484de32920fddcb17278664 (diff) | |
| download | lwn-cd7548ab360c462118568eebb8c6da3bc303b02e.tar.gz lwn-cd7548ab360c462118568eebb8c6da3bc303b02e.zip | |
thp: mprotect: transparent huge page support
Natively handle huge pmds when changing page tables on behalf of
mprotect().
I left out update_mmu_cache() because we do not need it on x86 anyway but
more importantly the interface works on ptes, not pmds.
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>
Diffstat (limited to 'mm/mprotect.c')
| -rw-r--r-- | mm/mprotect.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c index 9402080d0d4a..5a688a2756be 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -88,7 +88,13 @@ static inline void change_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 (next - addr != HPAGE_PMD_SIZE) + split_huge_page_pmd(vma->vm_mm, pmd); + else if (change_huge_pmd(vma, pmd, addr, newprot)) + continue; + /* fall through */ + } if (pmd_none_or_clear_bad(pmd)) continue; change_pte_range(vma->vm_mm, pmd, addr, next, newprot, |