mm: frontswap: fix a wrong if condition in frontswap_shrink

PATCH Zhenzhong Duan 2 participants 2 messages Sep 21, 2012 Memory management

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Zhenzhong Duan

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2012-09-21 03:28 UTC #0 lore raw

pages_to_unuse is set to 0 to unuse all frontswap pages But that doesn't happen since a wrong condition in frontswap_shrink cancels it.

Signed-off-by Zhenzhong Duan <[email protected]>

---
 mm/frontswap.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

mm/frontswap.c +2 -2

index 6b3e71a..db2a86f 100644
@@ -275,7 +275,7 @@ static int __frontswap_shrink(unsigned long target_pages,
 	if (total_pages <= target_pages) {
 		/* Nothing to do */
 		*pages_to_unuse = 0;
-		return 0;
+		return 1;
 	}
 	total_pages_to_unuse = total_pages - target_pages;
 	return __frontswap_unuse_pages(total_pages_to_unuse, pages_to_unuse, type);

@@ -302,7 +302,7 @@ void frontswap_shrink(unsigned long target_pages)
 	spin_lock(&swap_lock);
 	ret = __frontswap_shrink(target_pages, &pages_to_unuse, &type);
 	spin_unlock(&swap_lock);
-	if (ret == 0 && pages_to_unuse)
+	if (ret == 0)
 		try_to_unuse(type, true, pages_to_unuse);
 	return;
 }

Signature · 7 lines

1.7.3

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Dan Carpenter

2012-09-21 07:24 UTC #1 lore raw

Quoted 14 lines · Zhenzhong Duan

pages_to_unuse is set to 0 to unuse all frontswap pages But that doesn't happen since a wrong condition in frontswap_shrink cancels it.
Signed-off-by Zhenzhong Duan <[email protected]>
---
 mm/frontswap.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
mm/frontswap.c +0 -0
index 6b3e71a..db2a86f 100644

mm/frontswap.c static int __frontswap_shrink(unsigned long target_pages, · line 279

Quoted 6 lines

mm/frontswap.c +1 -1

@@ -275,7 +275,7 @@ static int __frontswap_shrink(unsigned long target_pages,
 	if (total_pages <= target_pages) {
 		/* Nothing to do */
 		*pages_to_unuse = 0;
-		return 0;
+		return 1;
 	}

This function used to return 0 or an error code. Could we add a comment at the top saying what the return values mean.

regards,
dan carpenter

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