[PATCH 01/22] HWPOISON: Add page flag for poisoned pages

From: Wu Fengguang
Date: Sun Jun 14 2009 - 23:16:36 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

Hardware poisoned pages need special handling in the VM and shouldn't be
touched again. This requires a new page flag. Define it here.

The page flags wars seem to be over, so it shouldn't be a problem
to get a new one.

v2: Add TestSetHWPoison (suggested by Johannes Weiner)
v3: Define TestSetHWPoison on !CONFIG_MEMORY_FAILURE (Fengguang)

Acked-by: Christoph Lameter <cl@xxxxxxxxx>
Reviewed-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

---
include/linux/page-flags.h | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)

--- sound-2.6.orig/include/linux/page-flags.h
+++ sound-2.6/include/linux/page-flags.h
@@ -51,6 +51,9 @@
* PG_buddy is set to indicate that the page is free and in the buddy system
* (see mm/page_alloc.c).
*
+ * PG_hwpoison indicates that a page got corrupted in hardware and contains
+ * data with incorrect ECC bits that triggered a machine check. Accessing is
+ * not safe since it may cause another machine check. Don't touch!
*/

/*
@@ -102,6 +105,9 @@ enum pageflags {
#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
PG_uncached, /* Page has been mapped as uncached */
#endif
+#ifdef CONFIG_MEMORY_FAILURE
+ PG_hwpoison, /* hardware poisoned page. Don't touch */
+#endif
__NR_PAGEFLAGS,

/* Filesystems */
@@ -182,6 +188,9 @@ static inline void ClearPage##uname(stru
#define __CLEARPAGEFLAG_NOOP(uname) \
static inline void __ClearPage##uname(struct page *page) { }

+#define TESTSETFLAG_FALSE(uname) \
+static inline int TestSetPage##uname(struct page *page) { return 0; }
+
#define TESTCLEARFLAG_FALSE(uname) \
static inline int TestClearPage##uname(struct page *page) { return 0; }

@@ -265,6 +274,16 @@ PAGEFLAG(Uncached, uncached)
PAGEFLAG_FALSE(Uncached)
#endif

+#ifdef CONFIG_MEMORY_FAILURE
+PAGEFLAG(HWPoison, hwpoison)
+TESTSETFLAG(HWPoison, hwpoison)
+#define __PG_HWPOISON (1UL << PG_hwpoison)
+#else
+PAGEFLAG_FALSE(HWPoison)
+TESTSETFLAG_FALSE(HWPoison)
+#define __PG_HWPOISON 0
+#endif
+
static inline int PageUptodate(struct page *page)
{
int ret = test_bit(PG_uptodate, &(page)->flags);
@@ -389,7 +408,7 @@ static inline void __ClearPageTail(struc
1 << PG_private | 1 << PG_private_2 | \
1 << PG_buddy | 1 << PG_writeback | 1 << PG_reserved | \
1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \
- 1 << PG_unevictable | __PG_MLOCKED)
+ 1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON)

/*
* Flags checked when a page is prepped for return by the page allocator.

--

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/