path: root/mm
diff options
authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2010-10-26 14:22:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-26 16:52:11 -0700
commit572438f9b52236bd8938b1647cc15e027d27ef55 (patch)
tree040d41121c01501a613d5f280b2d9fd6ef562447 /mm
parent44e2aa937e698ea95dd86b2a4fabd734ef2c76db (diff)
mm: fix is_mem_section_removable() page_order BUG_ON check
page_order() is called by memory hotplug's user interface to check the section is removable or not. (is_mem_section_removable()) It calls page_order() withoug holding zone->lock. So, even if the caller does if (PageBuddy(page)) ret = page_order(page) ... The caller may hit BUG_ON(). For fixing this, there are 2 choices. 1. add zone->lock. 2. remove BUG_ON(). is_mem_section_removable() is used for some "advice" and doesn't need to be 100% accurate. This is_removable() can be called via user program.. We don't want to take this important lock for long by user's request. So, this patch removes BUG_ON(). Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Wu Fengguang <fengguang.wu@intel.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/internal.h b/mm/internal.h
index 6a697bb97fc..dedb0aff673 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -62,7 +62,7 @@ extern bool is_free_buddy_page(struct page *page);
static inline unsigned long page_order(struct page *page)
- VM_BUG_ON(!PageBuddy(page));
+ /* PageBuddy() must be checked by the caller */
return page_private(page);