That static `nid' index needs locking.  Without it we can end up calling
alloc_pages_node() with an illegal node ID and the kernel crashes.

Acked-by: Gurudas Pai <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>
Signed-off-by: Willy Tarreau <[EMAIL PROTECTED]>
---
 mm/hugetlb.c |   15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 36db012..7c07eb2 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -101,13 +101,20 @@ static void free_huge_page(struct page *page)
 
 static int alloc_fresh_huge_page(void)
 {
-       static int nid = 0;
+       static int prev_nid;
        struct page *page;
-       page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN,
-                                       HUGETLB_PAGE_ORDER);
-       nid = next_node(nid, node_online_map);
+       static DEFINE_SPINLOCK(nid_lock);
+       int nid;
+
+       spin_lock(&nid_lock);
+       nid = next_node(prev_nid, node_online_map);
        if (nid == MAX_NUMNODES)
                nid = first_node(node_online_map);
+       prev_nid = nid;
+       spin_unlock(&nid_lock);
+
+       page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN,
+                                       HUGETLB_PAGE_ORDER);
        if (page) {
                set_compound_page_dtor(page, free_huge_page);
                spin_lock(&hugetlb_lock);
-- 
1.5.2.5

-- 
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