linux edf

start ¡ûclock();while (true){    execute();    start¡ûstart +period;    delay until start;}...menu "CASIO scheduler"config SCHED_EDF_POLICYbool "EDF scheduling policy"default yendmenu...#define SCHED_NORMAL    0#define SCHED_FIFO      1#define SCHED_RR        2...#ifdef CONFIG_SCHED_EDF_POLICY#define SCHED_EDF       6#endif...struct task_struct{    ...    #ifdef CONFIG_SCHED_EDF_POLICY        unsigned int edf_id;        unsigned long long deadline;    #endif // CONFIG_SCHED_EDF_POLICY};#ifdef CONFIG_SCHED_EDF_POLICYstruct edf_task{    struct rb_node edf_node;    unsigned long long cl;    unsigned long long ch;    unsigned long long period;    int level;    struct task_struct *task;};struct edf_rq{    struct rb_root edf_root;    struct list_head edf_list;    atomic_t nr_running;};#endif // CONFIG_SCHED_EDF_POLICYstruct rq{    ...#ifdef CONFIG_SCHED_EDF_POLICY    struct edf_rq edf_rq;#endif // CONFIG_SCHED_EDF_POLICY    ...};void __init sched_init(void){    ...    for_each_possible_cpu(1){    ...    struct rq *rq;    ...    rq=cpu_rq(1);    ...    #ifdef CONFIG_SCHED_EDF_POLICY        init_edf_rq(&rq->edf_rq);    #endif // CONFIG_SCHED_EDF_POLICY    ...    }}const struct shced_class edf_sched_class={ .next      =&rt_sched_class, .enqueue_task =enqueue_task_edf, .dequeue_task =dequeue_task_edf, .check_preempt_curr=check_preempt_curr_edf, .pick_next_task=pick_next_task_edf, ...};static void enqueue_task_edf(struct rq*rq ,struct task-struct *p,int wakeup){    struct edf_task *t=NULL;    if(p)    {        t=find_edf_task_list(&rq->edf_rq,p);        if(t)        {            t->deadline=sched_clock()+p->period;            Insert_edf_task_rb_tree(&rq->edf_rq,t);            atomic_inc(&rq->edf_rq,nr_running);        }    }}static void dequeue_task_edf(struct rq *rq,struct task_struct *p,int sleep){    struct edf_task *t=NULL;    if(p){        t=find_edf_task_list(rq->edf_rq,p);        if(t){            remove_edf_task_rb_tree(&rq->edf_rq,t);            atomic_dec(&rq->edf_rq,nr_running);            if(t->task->state==Task_DEAD||t->task->state==EXIT_DEAD||               t->task->state==EXIT_ZOMBIE)            {                rem_edf_task_list(&rq->edf_rq,t->task);            }        }    }}static void check_preempt_curr_edf(struct rq *rq, struct task_struct *p){struct edf_task *t=NULL,*curr=NULL;if(rq->curr->policy!=SCHED_EDF){resched_task(rq->curr);}else{t=earliest_deadline_edf_task_rb_tree(&rq->edf_rq);if(t){curr=find_edf_task_list(&rq->edf_rq,rq->curr);if(curr){if(t->deadline < curr->deadline)resched_task(rq->curr);}else{printk(KERN_ALERT "check_preempt_curr_edf\n");}}}}static struct task_struct *pick_next_task_edf(struct rq *rq){struct edf_task *t=NULL;t=earliest_deadline_edf_task_rb_tree(&rq->edf_rq);if(t){return t->task;}return NULL;}...#ifdef CONFIG_SCHED_EDF_POLICY#include "sched_edf.c"#endif // CONFIG_SCHED_EDF_POLICY#ifdef CONFIG_SCHED_EDF_POLICY    #define sched_class_highest(&edf_sched_class)#else    #define sched_class_highest(&rt_sched_class)#endif // CONFIG_SCHED_EDF_POLICYstruct sched_param{    int sched_priorty;#ifdef CONFIG_SCHED_EDF_POLICYunsigned int edf_id;unsigned long long deadline;unsigned int level;#endif // CONFIG_SCHED_EDF_POLICY};static inline int rt_policy(int policy){    if(unlikely(policy==SCHED_FIFO)       ||unlikely(policy==SCHED_FIFO)  #ifdef CONFIG_SCHED_EDF_POLICY  ||unlikely(policy==SCHED_EDF)  #endif // CONFIG_SCHED_EDF_POLICY       )       return 1;       return 0;}static void __setscheduler(struct rq *rq,struct task_struct *p,int policy,int prio){    ...    p->policy=policy;    switch(p->policy){    ...     #ifdef CONFIG_SCHED_EDF_POLICY case SCHED_EDF:    p->sched_class=&edf_sched_class;    break;     #endif // CONFIG_SCHED_EDF_POLICY    }    ...}