Commit 373fd236 authored by Hui Tang's avatar Hui Tang Committed by zhangchangzhong
Browse files

sched: Add static key to reduce noise 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7A718



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

Add static key to reduce noise when not enable dynamic affinity.
There are better performance in some case, such for lmbench.

Fixes: 243865da ("cpuset: Introduce new interface for scheduler ...")
Signed-off-by: default avatarHui Tang <tanghui20@huawei.com>
Reviewed-by: default avatarZhang Qiao <zhangqiao22@huawei.com>
Signed-off-by: default avatarZhang Changzhong <zhangchangzhong@huawei.com>
parent 822fb46b

include/linux/sched.h

+1 −0
Original line number Diff line number Diff line
@@ -2007,6 +2007,7 @@ int set_prefer_cpus_ptr(struct task_struct *p, 
			const struct cpumask *new_mask);

int sched_prefer_cpus_fork(struct task_struct *p, struct task_struct *orig);

void sched_prefer_cpus_free(struct task_struct *p);

void dynamic_affinity_enable(void);

#endif



#ifdef CONFIG_QOS_SCHED_SMART_GRID

kernel/cgroup/cpuset.c

+3 −0
Original line number Diff line number Diff line
@@ -625,6 +625,9 @@ static int update_prefer_cpumask(struct cpuset *cs, struct cpuset *trialcs, 


	update_tasks_prefer_cpumask(trialcs);



	if (!cpumask_empty(trialcs->prefer_cpus))

		dynamic_affinity_enable();



	spin_lock_irq(&callback_lock);

	cpumask_copy(cs->prefer_cpus, trialcs->prefer_cpus);

	spin_unlock_irq(&callback_lock);

kernel/sched/fair.c

+30 −2
Original line number Diff line number Diff line
@@ -7131,6 +7131,29 @@ static int wake_cap(struct task_struct *p, int cpu, int prev_cpu) 
}



#ifdef CONFIG_QOS_SCHED_DYNAMIC_AFFINITY



#ifdef CONFIG_JUMP_LABEL

static DEFINE_STATIC_KEY_FALSE(__dynamic_affinity_used);



static inline bool dynamic_affinity_used(void)

{

	return static_branch_unlikely(&__dynamic_affinity_used);

}



void dynamic_affinity_enable(void)

{

	static_branch_enable_cpuslocked(&__dynamic_affinity_used);

}



#else /* CONFIG_JUMP_LABEL */

static bool dynamic_affinity_used(void)

{

	return true;

}



void dynamic_affinity_enable(void) {}

#endif



/*

 * Low utilization threshold for CPU

 *
@@ -7246,6 +7269,8 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f 
	time = schedstat_start_time();



#ifdef CONFIG_QOS_SCHED_DYNAMIC_AFFINITY

	p->select_cpus = &p->cpus_allowed;

	if (dynamic_affinity_used())

		set_task_select_cpus(p, &idlest_cpu, sd_flag);

#endif
@@ -8272,7 +8297,10 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env) 
		return 0;



#ifdef CONFIG_QOS_SCHED_DYNAMIC_AFFINITY

	p->select_cpus = &p->cpus_allowed;

	if (dynamic_affinity_used())

		set_task_select_cpus(p, NULL, 0);



	if (!cpumask_test_cpu(env->dst_cpu, p->select_cpus)) {

#else

	if (!cpumask_test_cpu(env->dst_cpu, &p->cpus_allowed)) {