[PATCH] unpaged: unifdefed PageCompound
It looks like snd_xxx is not the only nopage to be using PageReserved as a way
of holding a high-order page together: which no longer works, but is masked by
our failure to free from VM_RESERVED areas. We cannot fix that bug without
first substituting another way to hold the high-order page together, while
farming out the 0-order pages from within it.
That's just what PageCompound is designed for, but it's been kept under
CONFIG_HUGETLB_PAGE. Remove the #ifdefs: which saves some space (out- of-line
put_page), doesn't slow down what most needs to be fast (already using
hugetlb), and unifies the way we handle high-order pages.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0986d19..9701210 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -311,8 +311,6 @@
extern void FASTCALL(__page_cache_release(struct page *));
-#ifdef CONFIG_HUGETLB_PAGE
-
static inline int page_count(struct page *page)
{
if (PageCompound(page))
@@ -329,23 +327,6 @@
void put_page(struct page *page);
-#else /* CONFIG_HUGETLB_PAGE */
-
-#define page_count(p) (atomic_read(&(p)->_count) + 1)
-
-static inline void get_page(struct page *page)
-{
- atomic_inc(&page->_count);
-}
-
-static inline void put_page(struct page *page)
-{
- if (put_page_testzero(page))
- __page_cache_release(page);
-}
-
-#endif /* CONFIG_HUGETLB_PAGE */
-
/*
* Multiple processes may "see" the same page. E.g. for untouched
* mappings of /dev/null, all processes see the same page full of
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index f34767c..343083f 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -287,11 +287,7 @@
#define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags)
#define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags)
-#ifdef CONFIG_HUGETLB_PAGE
#define PageCompound(page) test_bit(PG_compound, &(page)->flags)
-#else
-#define PageCompound(page) 0
-#endif
#define SetPageCompound(page) set_bit(PG_compound, &(page)->flags)
#define ClearPageCompound(page) clear_bit(PG_compound, &(page)->flags)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bd4de59..23b84c4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -148,10 +148,6 @@
add_taint(TAINT_BAD_PAGE);
}
-#ifndef CONFIG_HUGETLB_PAGE
-#define prep_compound_page(page, order) do { } while (0)
-#define destroy_compound_page(page, order) do { } while (0)
-#else
/*
* Higher-order pages are called "compound pages". They are structured thusly:
*
@@ -205,7 +201,6 @@
ClearPageCompound(p);
}
}
-#endif /* CONFIG_HUGETLB_PAGE */
/*
* function for dealing with page's order in buddy system.
diff --git a/mm/swap.c b/mm/swap.c
index d09cf7f..73d3514 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -34,8 +34,6 @@
/* How many pages do we try to swap or page in/out together? */
int page_cluster;
-#ifdef CONFIG_HUGETLB_PAGE
-
void put_page(struct page *page)
{
if (unlikely(PageCompound(page))) {
@@ -52,7 +50,6 @@
__page_cache_release(page);
}
EXPORT_SYMBOL(put_page);
-#endif
/*
* Writeback is about to end against a page which has been marked for immediate