diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 5653a3a5cd0eb259e17c6b1c068cc27069b06dee..7bc282428cc47188b516b5d14a71f0604d161443 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7942,6 +7942,34 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) return 0; } +/* + * Return true if task @p can migrate from @rq to @dst_rq in the same LLC. + * No need to test for co-locality, and no need to test task_hot(), as sharing + * LLC provides cache warmth at that level. + */ +static bool +can_migrate_task_llc(struct task_struct *p, struct rq *rq, struct rq *dst_rq) +{ + int dst_cpu = dst_rq->cpu; + + lockdep_assert_held(&rq->lock); + + if (throttled_lb_pair(task_group(p), cpu_of(rq), dst_cpu)) + return false; + + if (!cpumask_test_cpu(dst_cpu, p->cpus_ptr)) { + schedstat_inc(p->se.statistics.nr_failed_migrations_affine); + return false; + } + + if (task_running(rq, p)) { + schedstat_inc(p->se.statistics.nr_failed_migrations_running); + return false; + } + + return true; +} + /* * detach_task() -- detach the task for the migration from @src_rq to @dst_cpu. */