mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()

soft lockup in freeing gigantic hugepage fixed in commit 55f67141a892 "mm:
hugetlb: fix softlockup when a large number of hugepages are freed." can
happen in return_unused_surplus_pages(), so let's fix it.

Signed-off-by: Masayoshi Mizuma <[email protected]>
Signed-off-by: Naoya Horiguchi <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Aneesh Kumar <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index dd30f22b35e0c904b0fe9cfd4f550b810e1e7c22..246192929a2d5c4c4aa424e15c6a7b88e929e785 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1172,6 +1172,7 @@ static void return_unused_surplus_pages(struct hstate *h,
        while (nr_pages--) {
                if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1))
                        break;
+               cond_resched_lock(&hugetlb_lock);
        }
 }