[PATCH openEuler-1.0-LTS 1/2] sched/qos: Don't unthrottle cfs_rq when cfs_rq is throttled by qos

From: Zhang Qiao zhangqiao22@huawei.com

hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I64OUS CVE: NA

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When a cfs_rq throttled by qos, mark cfs_rq->throttled as 1, and cfs bw will unthrottled this cfs_rq by mistake, it cause a list_del_valid warning. So add macro QOS_THROTTLED(=2), when a cfs_rq is throttled by qos, we mark the cfs_rq->throttled as QOS_THROTTLED, will check the value of cfs_rq->throttled before unthrottle a cfs_rq.

Signed-off-by: Zhang Qiao zhangqiao22@huawei.com Reviewed-by: Chen Hui judy.chenhui@huawei.com Reviewed-by: zheng zucheng zhengzucheng@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- kernel/sched/fair.c | 59 ++++++++++++++++++++++++++------------------- 1 file changed, 34 insertions(+), 25 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index a34ca843bf0a..0dba06ce0677 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -103,6 +103,13 @@ int __weak arch_asym_cpu_priority(int cpu) #endif

#ifdef CONFIG_QOS_SCHED + +/* + * To distinguish cfs bw, use QOS_THROTTLED mark cfs_rq->throttled + * when qos throttled(and cfs bw throttle mark cfs_rq->throttled as 1). + */ +#define QOS_THROTTLED 2 + static DEFINE_PER_CPU_SHARED_ALIGNED(struct list_head, qos_throttled_cfs_rq); static DEFINE_PER_CPU_SHARED_ALIGNED(struct hrtimer, qos_overload_timer); static DEFINE_PER_CPU(int, qos_cpu_overload); @@ -4649,6 +4656,14 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)

se = cfs_rq->tg->se[cpu_of(rq)];

+#ifdef CONFIG_QOS_SCHED + /* + * if this cfs_rq throttled by qos, not need unthrottle it. + */ + if (cfs_rq->throttled == QOS_THROTTLED) + return; +#endif + cfs_rq->throttled = 0;

update_rq_clock(rq); @@ -7066,37 +7081,18 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ #ifdef CONFIG_QOS_SCHED static void start_qos_hrtimer(int cpu);

-static int qos_tg_unthrottle_up(struct task_group *tg, void *data) -{ - struct rq *rq = data; - struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)]; - - cfs_rq->throttle_count--; - - return 0; -} - -static int qos_tg_throttle_down(struct task_group *tg, void *data) -{ - struct rq *rq = data; - struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)]; - - cfs_rq->throttle_count++; - - return 0; -} - static void throttle_qos_cfs_rq(struct cfs_rq *cfs_rq) { struct rq *rq = rq_of(cfs_rq); struct sched_entity *se; long task_delta, idle_task_delta, dequeue = 1; + unsigned int prev_nr = rq->cfs.h_nr_running;

se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))];

/* freeze hierarchy runnable averages while throttled */ rcu_read_lock(); - walk_tg_tree_from(cfs_rq->tg, qos_tg_throttle_down, tg_nop, (void *)rq); + walk_tg_tree_from(cfs_rq->tg, tg_throttle_down, tg_nop, (void *)rq); rcu_read_unlock();

task_delta = cfs_rq->h_nr_running; @@ -7118,12 +7114,14 @@ static void throttle_qos_cfs_rq(struct cfs_rq *cfs_rq)

if (!se) { sub_nr_running(rq, task_delta); + if (prev_nr >= 2 && prev_nr - task_delta < 2) + overload_clear(rq); }

if (list_empty(&per_cpu(qos_throttled_cfs_rq, cpu_of(rq)))) start_qos_hrtimer(cpu_of(rq));

- cfs_rq->throttled = 1; + cfs_rq->throttled = QOS_THROTTLED;

list_add(&cfs_rq->qos_throttled_list, &per_cpu(qos_throttled_cfs_rq, cpu_of(rq))); @@ -7135,8 +7133,11 @@ static void unthrottle_qos_cfs_rq(struct cfs_rq *cfs_rq) struct sched_entity *se; int enqueue = 1; long task_delta, idle_task_delta; + unsigned int prev_nr = rq->cfs.h_nr_running;

se = cfs_rq->tg->se[cpu_of(rq)]; + if (cfs_rq->throttled != QOS_THROTTLED) + return;

cfs_rq->throttled = 0;

@@ -7145,7 +7146,7 @@ static void unthrottle_qos_cfs_rq(struct cfs_rq *cfs_rq)

/* update hierarchical throttle state */ rcu_read_lock(); - walk_tg_tree_from(cfs_rq->tg, tg_nop, qos_tg_unthrottle_up, (void *)rq); + walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq); rcu_read_unlock();

if (!cfs_rq->load.weight) @@ -7167,12 +7168,20 @@ static void unthrottle_qos_cfs_rq(struct cfs_rq *cfs_rq) break; }

- assert_list_leaf_cfs_rq(rq); - if (!se) { add_nr_running(rq, task_delta); + if (prev_nr < 2 && prev_nr + task_delta >= 2) + overload_set(rq); + } + + for_each_sched_entity(se) { + cfs_rq = cfs_rq_of(se); + + list_add_leaf_cfs_rq(cfs_rq); }

+ assert_list_leaf_cfs_rq(rq); + /* Determine whether we need to wake up potentially idle CPU: */ if (rq->curr == rq->idle && rq->cfs.nr_running) resched_curr(rq);