2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: KAMEZAWA Hiroyuki <[email protected]> commit 572438f9b52236bd8938b1647cc15e027d27ef55 upstream. 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 <[email protected]> Acked-by: Wu Fengguang <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Mel Gorman <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Andi Kleen <[email protected]> --- mm/internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux/mm/internal.h =================================================================== --- linux.orig/mm/internal.h +++ linux/mm/internal.h @@ -62,7 +62,7 @@ extern bool is_free_buddy_page(struct pa */ 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); } _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
