path: root/mm/page_alloc.c
diff options
authorLinus Torvalds <>2009-12-16 12:36:49 -0800
committerLinus Torvalds <>2009-12-16 12:36:49 -0800
commitd4220f987cf473c65a342ca69e3eb13dea919a49 (patch)
treedbb004a9c805d6de3f6e3955398fee1084a29f16 /mm/page_alloc.c
parent61cf693159d6a968a7014e24905143f71ed8ddcf (diff)
parentf2c03debdfb387fa2e35cac6382779072b8b9209 (diff)
Merge branch 'hwpoison' of git://
* 'hwpoison' of git:// (34 commits) HWPOISON: Remove stray phrase in a comment HWPOISON: Try to allocate migration page on the same node HWPOISON: Don't do early filtering if filter is disabled HWPOISON: Add a madvise() injector for soft page offlining HWPOISON: Add soft page offline support HWPOISON: Undefine short-hand macros after use to avoid namespace conflict HWPOISON: Use new shake_page in memory_failure HWPOISON: Use correct name for MADV_HWPOISON in documentation HWPOISON: mention HWPoison in Kconfig entry HWPOISON: Use get_user_page_fast in hwpoison madvise HWPOISON: add an interface to switch off/on all the page filters HWPOISON: add memory cgroup filter memcg: add accessor to mem_cgroup.css memcg: rename and export try_get_mem_cgroup_from_page() HWPOISON: add page flags filter mm: export stable page flags HWPOISON: limit hwpoison injector to known page types HWPOISON: add fs/device filters HWPOISON: return 0 to indicate success reliably HWPOISON: make semantics of IGNORED/DELAYED clear ...
Diffstat (limited to 'mm/page_alloc.c')
1 files changed, 21 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 850c4a7e2fe..74af449b1f1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5091,3 +5091,24 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
spin_unlock_irqrestore(&zone->lock, flags);
+bool is_free_buddy_page(struct page *page)
+ struct zone *zone = page_zone(page);
+ unsigned long pfn = page_to_pfn(page);
+ unsigned long flags;
+ int order;
+ spin_lock_irqsave(&zone->lock, flags);
+ for (order = 0; order < MAX_ORDER; order++) {
+ struct page *page_head = page - (pfn & ((1 << order) - 1));
+ if (PageBuddy(page_head) && page_order(page_head) >= order)
+ break;
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+ return order < MAX_ORDER;