1 files changed, 9 insertions, 1 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index cf8f100433e0..4da0f4bb2ca4 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4914,7 +4914,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
                                 SD_BALANCE_FORK |
                                 SD_BALANCE_EXEC |
                                 SD_SHARE_CPUPOWER |
-                                SD_SHARE_PKG_RESOURCES);
+                                SD_SHARE_PKG_RESOURCES |
+                                SD_PREFER_SIBLING);
                 if (nr_node_ids == 1)
                         pflags &= ~SD_SERIALIZE;
         }
@@ -5118,6 +5119,13 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
                         tmp->parent = parent->parent;
                         if (parent->parent)
                                 parent->parent->child = tmp;
+                        /*
+                         * Transfer SD_PREFER_SIBLING down in case of a
+                         * degenerate parent; the spans match for this
+                         * so the property transfers.
+                         */
+                        if (parent->flags & SD_PREFER_SIBLING)
+                                tmp->flags |= SD_PREFER_SIBLING;
                         destroy_sched_domain(parent, cpu);
                 } else
                         tmp = tmp->parent;