Commit 1621f465 authored by Zhang Qiao's avatar Zhang Qiao Committed by Wenyu Huang
Browse files

sched: Introduce qos scheduler for co-location 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8MF4R


CVE: NA

--------------------------------

In cloud-native hybrid deployment scenarios, online tasks must preempt
offline tasks in a timely and offline tasks can't affect the QoS of online
tasks, so we introduce the idea of qos level to scheduler, which now is
supported with different scheduler policies. The qos scheduler will change
the policy of correlative tasks when the qos level of a task group is
modified with cpu.qos_level cpu cgroup file. In this way we are able to
satisfy different needs of tasks in different qos levels.

The value of qos_level can be 0 or -1, default value is 0. If qos_level
is 0, the group is an online group. otherwise it is an offline group.

Signed-off-by: default avatarZhang Qiao <zhangqiao22@huawei.com>
Signed-off-by: default avatarWenyu Huang <huangwenyu5@huawei.com>
parent 7f55dbd9

init/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -985,6 +985,18 @@ menuconfig CGROUP_SCHED 
	  tasks.



if CGROUP_SCHED

config QOS_SCHED

	bool "Qos task scheduling"

	depends on CGROUP_SCHED

	depends on CFS_BANDWIDTH

	default n

	help

	  This option enable qos scheduler, and support co-location online

	  services (Latency Sensitive) and offline tasks. colocation can

	  effectively improve the resource utilization.



	  If in doubt, say N.



config FAIR_GROUP_SCHED

	bool "Group scheduling for SCHED_OTHER"

	depends on CGROUP_SCHED

kernel/sched/core.c

+120 −0
Original line number Diff line number Diff line
@@ -7727,6 +7727,18 @@ static int __sched_setscheduler(struct task_struct *p, 
	}

change:



#ifdef CONFIG_QOS_SCHED

	/*

	 * If the scheduling policy of an offline task is set to a policy

	 * other than SCHED_IDLE, the online task preemption and cpu resource

	 * isolation will be invalid, so return -EINVAL in this case.

	 */

	if (unlikely(task_group(p)->qos_level == -1 && !idle_policy(policy))) {

		retval = -EINVAL;

		goto unlock;

	}

#endif



	if (user) {

#ifdef CONFIG_RT_GROUP_SCHED

		/*
@@ -10345,6 +10357,35 @@ void ia64_set_curr_task(int cpu, struct task_struct *p) 
/* task_group_lock serializes the addition/removal of task groups */

static DEFINE_SPINLOCK(task_group_lock);



#ifdef CONFIG_QOS_SCHED

static inline int alloc_qos_sched_group(struct task_group *tg,

					struct task_group *parent)

{

	tg->qos_level = parent->qos_level;



	return 1;

}



static void sched_change_qos_group(struct task_struct *tsk, struct task_group *tg)

{

	struct sched_attr attr = {0};



	/*

	 * No need to re-setcheduler when a task is exiting or the task

	 * is in an autogroup.

	 */

	if (!(tsk->flags & PF_EXITING) &&

	    !task_group_is_autogroup(tg) &&

	    (tg->qos_level == -1)) {

		attr.sched_priority = 0;

		attr.sched_policy = SCHED_IDLE;

		attr.sched_nice = PRIO_TO_NICE(tsk->static_prio);

		__setscheduler_params(tsk, &attr);

		__setscheduler_prio(tsk, normal_prio(tsk));

	}

}

#endif



static inline void alloc_uclamp_sched_group(struct task_group *tg,

					    struct task_group *parent)

{
@@ -10395,6 +10436,11 @@ struct task_group *sched_create_group(struct task_group *parent) 
	if (!alloc_fair_sched_group(tg, parent))

		goto err;



#ifdef CONFIG_QOS_SCHED

	if (!alloc_qos_sched_group(tg, parent))

		goto err;

#endif



	if (!alloc_rt_sched_group(tg, parent))

		goto err;
@@ -10481,6 +10527,10 @@ static void sched_change_group(struct task_struct *tsk, struct task_group *group 
{

	tsk->sched_task_group = group;



#ifdef CONFIG_QOS_SCHED

	sched_change_qos_group(tsk, group);

#endif



#ifdef CONFIG_FAIR_GROUP_SCHED

	if (tsk->sched_class->task_change_group)

		tsk->sched_class->task_change_group(tsk);
@@ -11209,6 +11259,69 @@ static int cpu_idle_write_s64(struct cgroup_subsys_state *css, 
}

#endif



#ifdef CONFIG_QOS_SCHED

static int tg_change_scheduler(struct task_group *tg, void *data)

{

	int policy;

	struct css_task_iter it;

	struct sched_param param;

	struct task_struct *tsk;

	s64 qos_level = *(s64 *)data;

	struct cgroup_subsys_state *css = &tg->css;



	tg->qos_level = qos_level;

	if (qos_level == -1)

		policy = SCHED_IDLE;

	else

		policy = SCHED_NORMAL;



	param.sched_priority = 0;

	css_task_iter_start(css, 0, &it);

	while ((tsk = css_task_iter_next(&it)))

		sched_setscheduler(tsk, policy, &param);

	css_task_iter_end(&it);



	return 0;

}



static int cpu_qos_write(struct cgroup_subsys_state *css,

			 struct cftype *cftype, s64 qos_level)

{

	struct task_group *tg = css_tg(css);



	if (!tg->se[0])

		return -EINVAL;



	if (qos_level != -1 && qos_level != 0)

		return -EINVAL;



	if (tg->qos_level == qos_level)

		goto done;



	if (tg->qos_level == -1 && qos_level == 0)

		return -EINVAL;



	cpus_read_lock();

	if (qos_level == -1)

		cfs_bandwidth_usage_inc();

	else

		cfs_bandwidth_usage_dec();

	cpus_read_unlock();



	rcu_read_lock();

	walk_tg_tree_from(tg, tg_change_scheduler, tg_nop, (void *)(&qos_level));

	rcu_read_unlock();

done:

	return 0;

}



static inline s64 cpu_qos_read(struct cgroup_subsys_state *css,

			       struct cftype *cft)

{

	return css_tg(css)->qos_level;

}

#endif



static struct cftype cpu_legacy_files[] = {

#ifdef CONFIG_FAIR_GROUP_SCHED

	{
@@ -11272,6 +11385,13 @@ static struct cftype cpu_legacy_files[] = { 
		.seq_show = cpu_uclamp_max_show,

		.write = cpu_uclamp_max_write,

	},

#endif

#ifdef CONFIG_QOS_SCHED

	{

		.name = "qos_level",

		.read_s64 = cpu_qos_read,

		.write_s64 = cpu_qos_write,

	},

#endif

	{ }	/* Terminate */

};

kernel/sched/sched.h

+4 −0
Original line number Diff line number Diff line
@@ -403,6 +403,10 @@ struct task_group { 


	struct cfs_bandwidth	cfs_bandwidth;



#ifdef CONFIG_QOS_SCHED

	long qos_level;

#endif



#ifdef CONFIG_UCLAMP_TASK_GROUP

	/* The two decimal precision [%] value requested from user-space */

	unsigned int		uclamp_pct[UCLAMP_CNT];