From: Song Zhang <zhangsong34@huawei.com> euleros inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICIG0E CVE: NA -------------------- When priority load balance enabled for online/offline tasks co-location, offline tasks maybe starve to death by load balance detach_tasks() if env->loop exceed env->loop_max and can not be migrate to idle cpus. So we should set env->loop to 0 and detach offline tasks again. Signed-off-by: Song Zhang <zhangsong34@huawei.com> Confict: kernel/sched/fair.c Patch adaptation due to context changes Signed-off-by: yangjiaqi <yangjiaqi16@huawei.com> --- kernel/sched/fair.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index c4c3afa6e7b4..ea3be1ff723e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -11024,6 +11024,13 @@ static int detach_tasks(struct lb_env *env) #ifdef CONFIG_QOS_SCHED_PRIO_LB if (sysctl_sched_prio_load_balance_enabled && env->imbalance > 0) { + /* + * Avoid offline tasks starve to death if env->loop exceed + * env->loop_max, so we should set env->loop to 0 and detach + * offline tasks again. + */ + if (env->loop > env->loop_max) + env->loop = 0; loop++; if (loop == 1) { tasks = &env->src_rq->cfs_offline_tasks; -- 2.33.0