mm: page_alloc: generalize order handling in __free_pages_bootmem()

__free_pages_bootmem() used to special-case higher-order frees to save
individual page checking with free_pages_bulk().

Nowadays, both zero order and non-zero order frees use free_pages(), which
checks each individual page anyway, and so there is little point in making
the distinction anymore.  The higher-order loop will work just fine for
zero order pages.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 59153da..794e671 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -730,32 +730,23 @@ static void __free_pages_ok(struct page *page, unsigned int order)
        local_irq_restore(flags);
 }
 
-/*
- * permit the bootmem allocator to evade page validation on high-order frees
- */
 void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
 {
-       if (order == 0) {
-               __ClearPageReserved(page);
-               set_page_count(page, 0);
-               set_page_refcounted(page);
-               __free_page(page);
-       } else {
-               int loop;
-
-               prefetchw(page);
-               for (loop = 0; loop < (1 << order); loop++) {
-                       struct page *p = &page[loop];
+       unsigned int nr_pages = 1 << order;
+       unsigned int loop;
 
-                       if (loop + 1 < (1 << order))
-                               prefetchw(p + 1);
-                       __ClearPageReserved(p);
-                       set_page_count(p, 0);
-               }
+       prefetchw(page);
+       for (loop = 0; loop < nr_pages; loop++) {
+               struct page *p = &page[loop];
 
-               set_page_refcounted(page);
-               __free_pages(page, order);
+               if (loop + 1 < nr_pages)
+                       prefetchw(p + 1);
+               __ClearPageReserved(p);
+               set_page_count(p, 0);
        }
+
+       set_page_refcounted(page);
+       __free_pages(page, order);
 }