[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>

1 files changed, 0 insertions, 5 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bd4de592dc23..23b84c4e1a57 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -148,10 +148,6 @@ static void bad_page(const char *function, struct page *page)
         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 @@ static void destroy_compound_page(struct page *page, unsigned long order)
                 ClearPageCompound(p);
         }
 }
-#endif          /* CONFIG_HUGETLB_PAGE */
 
 /*
  * function for dealing with page's order in buddy system.