Commit 13e7444b authored by Nick Piggin's avatar Nick Piggin Committed by Linus Torvalds

[PATCH] mm: remove bad_range

bad_range is supposed to be a temporary check.  It would be a pity to throw it
out.  Make it depend on CONFIG_DEBUG_VM instead.

CONFIG_HOLES_IN_ZONE systems were relying on this to check pfn_valid in the
page allocator.  Add that to page_is_buddy instead.
Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 92be2e33
......@@ -172,7 +172,8 @@ config DEBUG_VM
bool "Debug VM"
depends on DEBUG_KERNEL
help
Enable this to debug the virtual-memory system.
Enable this to turn on extended checks in the virtual-memory system
that may impact performance.
If unsure, say N.
......
......@@ -81,6 +81,7 @@ int min_free_kbytes = 1024;
unsigned long __initdata nr_kernel_pages;
unsigned long __initdata nr_all_pages;
#ifdef CONFIG_DEBUG_VM
static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
{
int ret = 0;
......@@ -122,6 +123,13 @@ static int bad_range(struct zone *zone, struct page *page)
return 0;
}
#else
static inline int bad_range(struct zone *zone, struct page *page)
{
return 0;
}
#endif
static void bad_page(const char *function, struct page *page)
{
printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n",
......@@ -255,14 +263,20 @@ __find_combined_index(unsigned long page_idx, unsigned int order)
/*
* This function checks whether a page is free && is the buddy
* we can do coalesce a page and its buddy if
* (a) the buddy is free &&
* (b) the buddy is on the buddy system &&
* (c) a page and its buddy have the same order.
* (a) the buddy is not in a hole &&
* (b) the buddy is free &&
* (c) the buddy is on the buddy system &&
* (d) a page and its buddy have the same order.
* for recording page's order, we use page_private(page) and PG_private.
*
*/
static inline int page_is_buddy(struct page *page, int order)
{
#ifdef CONFIG_HOLES_IN_ZONE
if (!pfn_valid(page_to_pfn(page)))
return 0;
#endif
if (PagePrivate(page) &&
(page_order(page) == order) &&
page_count(page) == 0)
......@@ -314,17 +328,15 @@ static inline void __free_pages_bulk (struct page *page,
struct free_area *area;
struct page *buddy;
combined_idx = __find_combined_index(page_idx, order);
buddy = __page_find_buddy(page, page_idx, order);
if (bad_range(zone, buddy))
break;
if (!page_is_buddy(buddy, order))
break; /* Move the buddy up one level. */
list_del(&buddy->lru);
area = zone->free_area + order;
area->nr_free--;
rmv_page_order(buddy);
combined_idx = __find_combined_index(page_idx, order);
page = page + (combined_idx - page_idx);
page_idx = combined_idx;
order++;
......
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