Messages in this thread Patch in this message | | | From | Jia He <> | Subject | [RFC PATCH] mm/hugetlb: Avoid soft lockup in set_max_huge_pages() | Date | Tue, 26 Jul 2016 23:44:28 +0800 |
| |
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 <hejianet@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Paul Gortmaker <paul.gortmaker@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
| |