aboutsummaryrefslogtreecommitdiff
path: root/mm/memory-failure.c
diff options
context:
space:
mode:
authorXishi Qiu <qiuxishi@huawei.com>2013-02-22 16:33:59 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-23 17:50:15 -0800
commit0ebff32c3637e0ed551c017eb9599ac108ab36aa (patch)
treec6c85f235dac0a0f9f00b7f54f271ddb0a666f4b /mm/memory-failure.c
parent194159fbcc0d6ac1351837d3cd7a27a4af0219a6 (diff)
downloadlinux-0ebff32c3637e0ed551c017eb9599ac108ab36aa.tar.gz
memory-failure: fix an error of mce_bad_pages statistics
When doing $ echo paddr > /sys/devices/system/memory/soft_offline_page to offline a *free* page, the value of mce_bad_pages will be added, and the page is set HWPoison flag, but it is still managed by page buddy alocator. $ cat /proc/meminfo | grep HardwareCorrupted shows the value. If we offline the same page, the value of mce_bad_pages will be added *again*, this means the value is incorrect now. Assume the page is still free during this short time. soft_offline_page() get_any_page() "else if (is_free_buddy_page(p))" branch return 0 "goto done"; "atomic_long_add(1, &mce_bad_pages);" This patch: Move poisoned page check at the beginning of the function in order to fix the error. Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Tested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory-failure.c')
-rw-r--r--mm/memory-failure.c38
1 files changed, 17 insertions, 21 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index c6e4dd3e1c0..1a9242c5331 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1419,18 +1419,17 @@ static int soft_offline_huge_page(struct page *page, int flags)
unsigned long pfn = page_to_pfn(page);
struct page *hpage = compound_head(page);
+ if (PageHWPoison(hpage)) {
+ pr_info("soft offline: %#lx hugepage already poisoned\n", pfn);
+ return -EBUSY;
+ }
+
ret = get_any_page(page, pfn, flags);
if (ret < 0)
return ret;
if (ret == 0)
goto done;
- if (PageHWPoison(hpage)) {
- put_page(hpage);
- pr_info("soft offline: %#lx hugepage already poisoned\n", pfn);
- return -EBUSY;
- }
-
/* Keep page count to indicate a given hugepage is isolated. */
ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, false,
MIGRATE_SYNC);
@@ -1441,12 +1440,11 @@ static int soft_offline_huge_page(struct page *page, int flags)
return ret;
}
done:
- if (!PageHWPoison(hpage))
- atomic_long_add(1 << compound_trans_order(hpage),
- &mce_bad_pages);
+ /* keep elevated page count for bad page */
+ atomic_long_add(1 << compound_trans_order(hpage), &mce_bad_pages);
set_page_hwpoison_huge_page(hpage);
dequeue_hwpoisoned_huge_page(hpage);
- /* keep elevated page count for bad page */
+
return ret;
}
@@ -1488,6 +1486,11 @@ int soft_offline_page(struct page *page, int flags)
}
}
+ if (PageHWPoison(page)) {
+ pr_info("soft offline: %#lx page already poisoned\n", pfn);
+ return -EBUSY;
+ }
+
ret = get_any_page(page, pfn, flags);
if (ret < 0)
return ret;
@@ -1519,19 +1522,11 @@ int soft_offline_page(struct page *page, int flags)
return -EIO;
}
- lock_page(page);
- wait_on_page_writeback(page);
-
/*
* Synchronized using the page lock with memory_failure()
*/
- if (PageHWPoison(page)) {
- unlock_page(page);
- put_page(page);
- pr_info("soft offline: %#lx page already poisoned\n", pfn);
- return -EBUSY;
- }
-
+ lock_page(page);
+ wait_on_page_writeback(page);
/*
* Try to invalidate first. This should work for
* non dirty unmapped page cache pages.
@@ -1583,8 +1578,9 @@ int soft_offline_page(struct page *page, int flags)
return ret;
done:
+ /* keep elevated page count for bad page */
atomic_long_add(1, &mce_bad_pages);
SetPageHWPoison(page);
- /* keep elevated page count for bad page */
+
return ret;
}