diff options
| author | Andrea Arcangeli | 2011-01-13 15:47:16 -0800 |
|---|---|---|
| committer | Linus Torvalds | 2011-01-13 17:32:47 -0800 |
| commit | 37c2ac7872a9387542616f658d20ac25f5bdb32e (patch) | |
| tree | d115915db4a61e261012bf0f9c4cf14630243d71 /include | |
| parent | 91600e9e592e48736e630851c83da2ad6bf0e91f (diff) | |
thp: compound_trans_order
Read compound_trans_order safe. Noop for CONFIG_TRANSPARENT_HUGEPAGE=n.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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/mm.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 9c2695beab86..ce97a2bb0b19 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -450,6 +450,20 @@ static inline int compound_order(struct page *page) return (unsigned long)page[1].lru.prev; } +static inline int compound_trans_order(struct page *page) +{ + int order; + unsigned long flags; + + if (!PageHead(page)) + return 0; + + flags = compound_lock_irqsave(page); + order = compound_order(page); + compound_unlock_irqrestore(page, flags); + return order; +} + static inline void set_compound_order(struct page *page, unsigned long order) { page[1].lru.prev = (void *)order; |