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* [PATCH V4 1/3] MCE: fix an error of mce_bad_pages statistics
@ 2012-12-12  3:35 Xishi Qiu
  2012-12-12 15:46 ` Naoya Horiguchi
  2012-12-14  2:14 ` [PATCH V4 1/3 RESEND] " Xishi Qiu
  0 siblings, 2 replies; 3+ messages in thread
From: Xishi Qiu @ 2012-12-12  3:35 UTC (permalink / raw)
  To: WuJianguo, Xishi Qiu, Liujiang, Simon Jeons, Andrew Morton,
	Borislav Petkov, Andi Kleen, Fengguang Wu, Wanpeng Li, linux-mm,
	linux-kernel

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>
---
 mm/memory-failure.c |   38 +++++++++++++++++---------------------
 1 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 8b20278..3a8b4b2 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.
@@ -1582,8 +1577,9 @@ 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;
 }
-- 
1.7.1



^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH V4 1/3] MCE: fix an error of mce_bad_pages statistics
  2012-12-12  3:35 [PATCH V4 1/3] MCE: fix an error of mce_bad_pages statistics Xishi Qiu
@ 2012-12-12 15:46 ` Naoya Horiguchi
  2012-12-14  2:14 ` [PATCH V4 1/3 RESEND] " Xishi Qiu
  1 sibling, 0 replies; 3+ messages in thread
From: Naoya Horiguchi @ 2012-12-12 15:46 UTC (permalink / raw)
  To: qiuxishi
  Cc: wujianguo, jiang.liu, simon.jeons, Andrew Morton, bp, Andi Kleen,
	Wu Fengguang, liwanp, linux-mm, linux-kernel

On Wed, Dec 12, 2012 at 11:35:25AM +0800, Xishi Qiu wrote:
> Move poisoned page check at the beginning of the function in order to
> fix the error.

Thanks for the fix.
It works fine both on normal pages and hugepages in my testing.

Tested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>

Just nitpick below ...

> Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
> Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
> ---
>  mm/memory-failure.c |   38 +++++++++++++++++---------------------
>  1 files changed, 17 insertions(+), 21 deletions(-)
> 
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 8b20278..3a8b4b2 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 */
> +

I think this comment refers to "returning without decrementing page refcount",
and it's not about mce_bad_pages, so keeping the comment as it is seems good
for me.

>  	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.
> @@ -1582,8 +1577,9 @@ 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;
>  }

Ditto here.

Thanks,
Naoya

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH V4 1/3 RESEND] MCE: fix an error of mce_bad_pages statistics
  2012-12-12  3:35 [PATCH V4 1/3] MCE: fix an error of mce_bad_pages statistics Xishi Qiu
  2012-12-12 15:46 ` Naoya Horiguchi
@ 2012-12-14  2:14 ` Xishi Qiu
  1 sibling, 0 replies; 3+ messages in thread
From: Xishi Qiu @ 2012-12-14  2:14 UTC (permalink / raw)
  To: Xishi Qiu, WuJianguo, Liujiang, Simon Jeons, Andrew Morton,
	Borislav Petkov, Andi Kleen, Fengguang Wu, Wanpeng Li,
	n-horiguchi, linux-mm, linux-kernel

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>
---
 mm/memory-failure.c |   38 +++++++++++++++++---------------------
 1 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 8b20278..3a8b4b2 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.
@@ -1582,8 +1577,9 @@ 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;
 }
-- 
1.7.1



.



^ permalink raw reply related	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2012-12-14  2:15 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2012-12-12  3:35 [PATCH V4 1/3] MCE: fix an error of mce_bad_pages statistics Xishi Qiu
2012-12-12 15:46 ` Naoya Horiguchi
2012-12-14  2:14 ` [PATCH V4 1/3 RESEND] " Xishi Qiu

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