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| author | Wu Fengguang <fengguang.wu@intel.com> | 2009-12-16 12:19:58 +0100 |
|---|---|---|
| committer | Andi Kleen <ak@linux.intel.com> | 2009-12-16 12:19:58 +0100 |
| commit | 8d22ba1b74aa9420b6032d856446564fb21f8090 (patch) | |
| tree | 6c2e2d27e81d784faa0481500f1cecc613ff1167 /mm | |
| parent | 95d01fc664b9476e0d18e3d745bb209a42a33588 (diff) | |
| download | linux-8d22ba1b74aa9420b6032d856446564fb21f8090.tar.gz linux-8d22ba1b74aa9420b6032d856446564fb21f8090.tar.bz2 linux-8d22ba1b74aa9420b6032d856446564fb21f8090.zip | |
HWPOISON: detect free buddy pages explicitly
Most free pages in the buddy system have no PG_buddy set.
Introduce is_free_buddy_page() for detecting them reliably.
CC: Nick Piggin <npiggin@suse.de>
CC: Mel Gorman <mel@linux.vnet.ibm.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/internal.h | 3 | ||||
| -rw-r--r-- | mm/memory-failure.c | 9 | ||||
| -rw-r--r-- | mm/page_alloc.c | 21 |
3 files changed, 31 insertions, 2 deletions
diff --git a/mm/internal.h b/mm/internal.h index 4fe67a162cb4..49b2ff776b78 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -50,6 +50,9 @@ extern void putback_lru_page(struct page *page); */ extern void __free_pages_bootmem(struct page *page, unsigned int order); extern void prep_compound_page(struct page *page, unsigned long order); +#ifdef CONFIG_MEMORY_FAILURE +extern bool is_free_buddy_page(struct page *page); +#endif /* diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 676ab394200e..5055b940df5f 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -807,8 +807,13 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) */ if (!(flags & MF_COUNT_INCREASED) && !get_page_unless_zero(compound_head(p))) { - action_result(pfn, "free or high order kernel", IGNORED); - return PageBuddy(compound_head(p)) ? 0 : -EBUSY; + if (is_free_buddy_page(p)) { + action_result(pfn, "free buddy", DELAYED); + return 0; + } else { + action_result(pfn, "high order kernel", IGNORED); + return -EBUSY; + } } /* diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 59d2e88fb47c..6867b4d391fd 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5081,3 +5081,24 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) spin_unlock_irqrestore(&zone->lock, flags); } #endif + +#ifdef CONFIG_MEMORY_FAILURE +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; +} +#endif |