diff options
| -rw-r--r-- | kernel/sched_fair.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 4c6dae17cd1e..98e103988aad 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -2791,6 +2791,7 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, * 1) running (obviously), or * 2) cannot be migrated to this CPU due to cpus_allowed, or * 3) are cache-hot on their current CPU. + * 4) p->pi_lock is held. */ if (!cpumask_test_cpu(this_cpu, tsk_cpus_allowed(p))) { schedstat_inc(p, se.statistics.nr_failed_migrations_affine); @@ -2804,6 +2805,14 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, } /* + * rt -> fair class change may be in progress. If we sneak in should + * double_lock_balance() release rq->lock, and move the task, we will + * cause switched_to_fair() to meet a passed but no longer valid rq. + */ + if (raw_spin_is_locked(&p->pi_lock)) + return 0; + + /* * Aggressive migration if: * 1) task is cache cold, or * 2) too many balance attempts have failed. |