User can change a node specific hugetlb count. i.e. /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages the calculated value of count is a total number of huge pages. It could be overflow when a user entering a crazy high value. If so, the total number of huge pages could be a small value which is not user expect. We can simply fix it by setting count to ULONG_MAX, then it goes on. This may be more in line with user's intention of allocating as many huge pages as possible. Signed-off-by: Jing Xiangfeng <jingxiangfeng@xxxxxxxxxx> --- mm/hugetlb.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index afef616..6688894 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2423,7 +2423,14 @@ static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, * per node hstate attribute: adjust count to global, * but restrict alloc/free to the specified node. */ + unsigned long old_count = count; count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; + /* + * If user specified count causes overflow, set to + * largest possible value. + */ + if (count < old_count) + count = ULONG_MAX; init_nodemask_of_node(nodes_allowed, nid); } else nodes_allowed = &node_states[N_MEMORY]; -- 2.7.4
