In large memory(32TB) powerpc servers, we watched several soft lockup under stress tests. The call trace are as follows: 1. get_page_from_freelist+0x2d8/0xd50 __alloc_pages_nodemask+0x180/0xc20 alloc_fresh_huge_page+0xb0/0x190 set_max_huge_pages+0x164/0x3b0
2. prep_new_huge_page+0x5c/0x100 alloc_fresh_huge_page+0xc8/0x190 set_max_huge_pages+0x164/0x3b0 This patch is to fix such soft lockup. I thouhgt it is safe to call cond_resched() because alloc_fresh_gigantic_page and alloc_fresh_huge_page are out of spin_lock/unlock section. Signed-off-by: Jia He <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Naoya Horiguchi <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Paul Gortmaker <[email protected]> --- mm/hugetlb.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index addfe4ac..d51759d 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1146,6 +1146,10 @@ static int alloc_fresh_gigantic_page(struct hstate *h, for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { page = alloc_fresh_gigantic_page_node(h, node); + + /* yield cpu */ + cond_resched(); + if (page) return 1; } @@ -1381,6 +1385,10 @@ static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed) for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { page = alloc_fresh_huge_page_node(h, node); + + /* yield cpu */ + cond_resched(); + if (page) { ret = 1; break; -- 2.5.0
