[05/17] More compound page features

clameter
2007-04-24T22:24:57Z

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Add a couple of more compound functions to avoid having to duplicate code in various places.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

---
include/linux/mm.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)

Index: linux-2.6.21-rc7/include/linux/mm.h
===================================================================
--- linux-2.6.21-rc7.orig/include/linux/mm.h 2007-04-24 11:33:34.000000000 -0700
+++ linux-2.6.21-rc7/include/linux/mm.h 2007-04-24 11:32:16.000000000 -0700
@@ -330,6 +330,21 @@ static inline int compound_order(struct
return (unsigned long)page[1].lru.prev;
}

+static inline int compound_pages(struct page *page)
+{
+ return 1 << compound_order(page);
+}
+
+static inline int compound_shift(struct page *page)
+{
+ return PAGE_SHIFT + compound_order(page);
+}
+
+static inline int compound_size(struct page *page)
+{
+ return PAGE_SIZE << compound_order(page);
+}
+
/*
* Multiple processes may "see" the same page. E.g. for untouched
* mappings of /dev/null, all processes see the same page full of

--