本文主要是介绍Linux Kernel调度管理之rq，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
rq是描述就绪队列，其设计为每个cpu一个就绪队列，本地进程在本地队列上排序：
/* * This is the main, per-CPU runqueue data structure. * * Locking rule: those places that want to lock multiple runqueues * (such as the load balancing or the thread migration code), lock * acquire operations must be ordered by ascending &runqueue. */ struct rq { /* runqueue lock: */ raw_spinlock_t lock; /* * nr_running and cpu_load should be in the same cacheline because * remote CPUs use both these fields when doing load calculation. */ unsigned int nr_running; #ifdef CONFIG_NUMA_BALANCING unsigned int nr_numa_running; unsigned int nr_preferred_running; #endif #define CPU_LOAD_IDX_MAX 5 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; #ifdef CONFIG_NO_HZ_COMMON #ifdef CONFIG_SMP unsigned long last_load_update_tick; #endif /* CONFIG_SMP */ unsigned long nohz_flags; #endif /* CONFIG_NO_HZ_COMMON */ #ifdef CONFIG_NO_HZ_FULL unsigned long last_sched_tick; #endif /* capture load from *all* tasks on this cpu: */ struct load_weight load; unsigned long nr_load_updates; u64 nr_switches; struct cfs_rq cfs; struct rt_rq rt; struct dl_rq dl; #ifdef CONFIG_FAIR_GROUP_SCHED /* list of leaf cfs_rq on this cpu: */ struct list_head leaf_cfs_rq_list; #endif /* CONFIG_FAIR_GROUP_SCHED */ /* * This is part of a global counter where only the total sum * over all CPUs matters. A task can increase this counter on * one CPU and if it got migrated afterwards it may decrease * it on another CPU. Always updated under the runqueue lock: */ unsigned long nr_uninterruptible; struct task_struct *curr, *idle, *stop; unsigned long next_balance; struct mm_struct *prev_mm; unsigned int clock_skip_update; u64 clock; u64 clock_task; atomic_t nr_iowait; #ifdef CONFIG_SMP struct root_domain *rd; struct sched_domain *sd; unsigned long cpu_capacity; unsigned long cpu_capacity_orig; struct callback_head *balance_callback; unsigned char idle_balance; /* For active balancing */ int active_balance; int push_cpu; struct cpu_stop_work active_balance_work; /* cpu of this runqueue: */ int cpu; int online; struct list_head cfs_tasks; u64 rt_avg; u64 age_stamp; u64 idle_stamp; u64 avg_idle; /* This is used to determine avg_idle's max value */ u64 max_idle_balance_cost; #endif #ifdef CONFIG_IRQ_TIME_ACCOUNTING u64 prev_irq_time; #endif #ifdef CONFIG_PARAVIRT u64 prev_steal_time; #endif #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING u64 prev_steal_time_rq; #endif /* calc_load related fields */ unsigned long calc_load_update; long calc_load_active; #ifdef CONFIG_SCHED_HRTICK #ifdef CONFIG_SMP int hrtick_csd_pending; struct call_single_data hrtick_csd; #endif struct hrtimer hrtick_timer; #endif #ifdef CONFIG_SCHEDSTATS /* latency stats */ struct sched_info rq_sched_info; unsigned long long rq_cpu_time; /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ /* sys_sched_yield() stats */ unsigned int yld_count; /* schedule() stats */ unsigned int sched_count; unsigned int sched_goidle; /* try_to_wake_up() stats */ unsigned int ttwu_count; unsigned int ttwu_local; #endif #ifdef CONFIG_SMP struct llist_head wake_list; #endif #ifdef CONFIG_CPU_IDLE /* Must be inspected within a rcu lock section */ struct cpuidle_state *idle_state; #endif };
定义每个CPU就绪队列
DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
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