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authorAndrea Arcangeli <aarcange@redhat.com>2011-11-02 13:37:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-11-02 16:06:58 -0700
commitb35a35b556f5e6b7993ad0baf20173e75c09ce8c (patch)
tree85ea46dde6e97d4c73b724698fd65a403529953e /include/linux/mm.h
parente0d85a366c2300efd230ef82a9b22110b0658331 (diff)
thp: share get_huge_page_tail()
This avoids duplicating the function in every arch gup_fast. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mm.h')
-rw-r--r--include/linux/mm.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index f81b7b41930..3dc3a8c2c48 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -376,6 +376,17 @@ static inline int page_count(struct page *page)
return atomic_read(&compound_head(page)->_count);
}
+static inline void get_huge_page_tail(struct page *page)
+{
+ /*
+ * __split_huge_page_refcount() cannot run
+ * from under us.
+ */
+ VM_BUG_ON(page_mapcount(page) < 0);
+ VM_BUG_ON(atomic_read(&page->_count) != 0);
+ atomic_inc(&page->_mapcount);
+}
+
extern bool __get_page_tail(struct page *page);
static inline void get_page(struct page *page)