[PATCH 01/15] HWPOISON: Add page flag for poisoned pages

From: Wu Fengguang <fengguang.wu@intel.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Christoph Lameter <cl@linux.com>, Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: "Wu, Fengguang" <fengguang.wu@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Nick Piggin <npiggin@suse.de>,
	Hugh Dickins <hugh.dickins@tiscali.co.uk>,
	Andi Kleen <andi@firstfloor.org>,
	"riel@redhat.com" <riel@redhat.com>,
	"chris.mason@oracle.com" <chris.mason@oracle.com>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: [PATCH 01/15] HWPOISON: Add page flag for poisoned pages
Date: Sat, 20 Jun 2009 11:16:09 +0800	[thread overview]
Message-ID: <20090620031624.692166383@intel.com> (raw)
In-Reply-To: 20090620031608.624240019@intel.com

[-- Attachment #1: page-flag-poison --]
[-- Type: text/plain, Size: 2585 bytes --]

From: Andi Kleen <ak@linux.intel.com>

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@linux.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
 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.

-- 

