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| author | Andrea Arcangeli <aarcange@redhat.com> | 2011-01-13 15:46:32 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 17:32:39 -0800 |
| commit | 9180706344487700b40da9eca5dedd3d11cb33b4 (patch) | |
| tree | eb0347efe7e40adc78a271752c7382aa67875d6a /arch/powerpc/mm/gup.c | |
| parent | e9da73d67729b58bba256123e2b4651e0d8a01ac (diff) | |
| download | blackbird-obmc-linux-9180706344487700b40da9eca5dedd3d11cb33b4.tar.gz blackbird-obmc-linux-9180706344487700b40da9eca5dedd3d11cb33b4.zip | |
thp: alter compound get_page/put_page
Alter compound get_page/put_page to keep references on subpages too, in
order to allow __split_huge_page_refcount to split an hugepage even while
subpages have been pinned by one of the get_user_pages() variants.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/powerpc/mm/gup.c')
| -rw-r--r-- | arch/powerpc/mm/gup.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/powerpc/mm/gup.c b/arch/powerpc/mm/gup.c index d7efdbf640c7..fec13200868f 100644 --- a/arch/powerpc/mm/gup.c +++ b/arch/powerpc/mm/gup.c @@ -16,6 +16,16 @@ #ifdef __HAVE_ARCH_PTE_SPECIAL +static inline void get_huge_page_tail(struct page *page) +{ + /* + * __split_huge_page_refcount() cannot run + * from under us. + */ + VM_BUG_ON(atomic_read(&page->_count) < 0); + atomic_inc(&page->_count); +} + /* * The performance critical leaf functions are made noinline otherwise gcc * inlines everything into a single function which results in too much @@ -47,6 +57,8 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, put_page(page); return 0; } + if (PageTail(page)) + get_huge_page_tail(page); pages[*nr] = page; (*nr)++; |
