diff options
| -rw-r--r-- | kernel/sched/fair.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index df77c605c7a6..c11e36ff5ea0 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1201,9 +1201,21 @@ static int task_numa_migrate(struct task_struct *p) */ rcu_read_lock(); sd = rcu_dereference(per_cpu(sd_numa, env.src_cpu)); - env.imbalance_pct = 100 + (sd->imbalance_pct - 100) / 2; + if (sd) + env.imbalance_pct = 100 + (sd->imbalance_pct - 100) / 2; rcu_read_unlock(); + /* + * Cpusets can break the scheduler domain tree into smaller + * balance domains, some of which do not cross NUMA boundaries. + * Tasks that are "trapped" in such domains cannot be migrated + * elsewhere, so there is no point in (re)trying. + */ + if (unlikely(!sd)) { + p->numa_preferred_nid = cpu_to_node(task_cpu(p)); + return -EINVAL; + } + taskweight = task_weight(p, env.src_nid); groupweight = group_weight(p, env.src_nid); update_numa_stats(&env.src_stats, env.src_nid); |