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 <hejia...@gmail.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Naoya Horiguchi <n-horigu...@ah.jp.nec.com>
Cc: Mike Kravetz <mike.krav...@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>
Cc: Michal Hocko <mho...@suse.com>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: Paul Gortmaker <paul.gortma...@windriver.com>
---
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
