From: Huang Shijie <shijie8@gmail.com>
To: akpm@linux-foundation.org
Cc: mel@csn.ul.ie, linux-mm@kvack.org, Huang Shijie <shijie8@gmail.com>
Subject: [PATCH] mm : add check for the return value
Date: Mon, 4 Jan 2010 10:22:10 +0800 [thread overview]
Message-ID: <1262571730-2778-1-git-send-email-shijie8@gmail.com> (raw)
When the `page' returned by __rmqueue() is NULL, the origin code
still adds -(1 << order) to zone's NR_FREE_PAGES item.
The patch fixes it.
Signed-off-by: Huang Shijie <shijie8@gmail.com>
---
mm/page_alloc.c | 10 +++++++---
1 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4e9f5cc..620921d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1222,10 +1222,14 @@ again:
}
spin_lock_irqsave(&zone->lock, flags);
page = __rmqueue(zone, order, migratetype);
- __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
- spin_unlock(&zone->lock);
- if (!page)
+ if (likely(page)) {
+ __mod_zone_page_state(zone, NR_FREE_PAGES,
+ -(1 << order));
+ spin_unlock(&zone->lock);
+ } else {
+ spin_unlock(&zone->lock);
goto failed;
+ }
}
__count_zone_vm_events(PGALLOC, zone, 1 << order);
--
1.6.5.2
--
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next reply other threads:[~2010-01-04 2:22 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-04 2:22 Huang Shijie [this message]
2010-01-04 3:21 ` [PATCH] mm : add check for the return value Minchan Kim
2010-01-04 4:10 ` shijie8
2010-01-04 4:48 ` Minchan Kim
2010-01-04 5:18 ` Huang Shijie
2010-01-04 6:06 ` Minchan Kim
2010-01-08 22:59 ` Andrew Morton
2010-01-04 5:52 ` [PATCH] page allocator: fix update NR_FREE_PAGES only as necessary KOSAKI Motohiro
2010-01-04 6:03 ` Minchan Kim
2010-01-04 6:11 ` Huang Shijie
2010-01-04 6:16 ` KOSAKI Motohiro
2010-01-04 9:35 ` Huang Shijie
2010-01-05 7:24 ` KOSAKI Motohiro
2010-01-04 9:58 ` Mel Gorman
2010-01-04 17:46 ` Christoph Lameter
2010-01-05 1:08 ` KOSAKI Motohiro
2010-01-08 23:02 ` Andrew Morton
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