[PATCH V2] MCE: fix an error of mce_bad_pages statistics

From: Xishi Qiu
Date: Fri Dec 07 2012 - 03:48:59 EST

On x86 platform, if we use "/sys/devices/system/memory/soft_offline_page" to offline a
free page twice, the value of mce_bad_pages will be added twice. So this is an error,
since the page was already marked HWPoison, we should skip the page and don't add the
value of mce_bad_pages.

$ cat /proc/meminfo | grep HardwareCorrupted

atomic_long_add(1, &mce_bad_pages)

Signed-off-by: Xishi Qiu <qiuxishi@xxxxxxxxxx>
ïSigned-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
mm/memory-failure.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 8b20278..de760ca 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1582,8 +1582,11 @@ int soft_offline_page(struct page *page, int flags)
return ret;

- atomic_long_add(1, &mce_bad_pages);
- SetPageHWPoison(page);
/* keep elevated page count for bad page */
+ if (!PageHWPoison(page)) {
+ atomic_long_add(1, &mce_bad_pages);
+ SetPageHWPoison(page);
+ }
return ret;

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