include/nucleus/sched.h

Go to the documentation of this file.

#ifndef _XENO_NUCLEUS_SCHED_H
#define _XENO_NUCLEUS_SCHED_H

#include <nucleus/thread.h>

#if defined(__KERNEL__) || defined(__XENO_SIM__)

#include <nucleus/schedqueue.h>
#include <nucleus/sched-tp.h>
#include <nucleus/sched-sporadic.h>

/* Sched status flags */
#define XNKCOUT         0x80000000      /* Sched callout context */
#define XNINTCK         0x40000000      /* In master tick handler context */
#define XNSWLOCK        0x20000000      /* In context switch */
#define XNRESCHED       0x10000000      /* Needs rescheduling */

/* Sched local flags */
#define XNHTICK         0x00008000      /* Host tick pending  */
#define XNINIRQ         0x00004000      /* In IRQ handling context */
#define XNHDEFER        0x00002000      /* Host tick deferred */

/* Sched RPI status flags */
#define XNRPICK         0x80000000      /* Check RPI state */

struct xnsched_rt {
        xnsched_queue_t runnable;       
#ifdef CONFIG_XENO_OPT_PRIOCPL
        xnsched_queue_t relaxed;        
#endif /* CONFIG_XENO_OPT_PRIOCPL */
};

typedef struct xnsched {

        xnflags_t status;               
        xnflags_t lflags;               
        int cpu;
        struct xnthread *curr;          
#ifdef CONFIG_SMP
        xnarch_cpumask_t resched;       
#endif

        struct xnsched_rt rt;           
#ifdef CONFIG_XENO_OPT_SCHED_TP
        struct xnsched_tp tp;           
#endif
#ifdef CONFIG_XENO_OPT_SCHED_SPORADIC
        struct xnsched_sporadic pss;    
#endif

        xntimerq_t timerqueue;          /* !< Core timer queue. */
        volatile unsigned inesting;     
        struct xntimer htimer;          
        struct xnthread *zombie;
        struct xnthread rootcb;         
#ifdef CONFIG_XENO_HW_UNLOCKED_SWITCH
        struct xnthread *last;
#endif

#ifdef CONFIG_XENO_HW_FPU
        struct xnthread *fpuholder;     
#endif

#ifdef CONFIG_XENO_OPT_WATCHDOG
        struct xntimer wdtimer; 
        int wdcount;            
#endif

#ifdef CONFIG_XENO_OPT_STATS
        xnticks_t last_account_switch;  
        xnstat_exectime_t *current_account;     
#endif

#ifdef CONFIG_XENO_OPT_PRIOCPL
        DECLARE_XNLOCK(rpilock);        
        xnflags_t rpistatus;
#endif

#ifdef CONFIG_XENO_OPT_PERVASIVE
        struct task_struct *gatekeeper;
        wait_queue_head_t gkwaitq;
        struct linux_semaphore gksync;
        struct xnthread *gktarget;
#endif

} xnsched_t;

union xnsched_policy_param;

struct xnsched_class {

        void (*sched_init)(struct xnsched *sched);
        void (*sched_enqueue)(struct xnthread *thread);
        void (*sched_dequeue)(struct xnthread *thread);
        void (*sched_requeue)(struct xnthread *thread);
        struct xnthread *(*sched_pick)(struct xnsched *sched);
        void (*sched_tick)(struct xnthread *curr);
        void (*sched_rotate)(struct xnsched *sched,
                             const union xnsched_policy_param *p);
        void (*sched_migrate)(struct xnthread *thread,
                              struct xnsched *sched);
        void (*sched_setparam)(struct xnthread *thread,
                               const union xnsched_policy_param *p);
        void (*sched_getparam)(struct xnthread *thread,
                               union xnsched_policy_param *p);
        void (*sched_trackprio)(struct xnthread *thread,
                                const union xnsched_policy_param *p);
        int (*sched_declare)(struct xnthread *thread,
                             const union xnsched_policy_param *p);
        void (*sched_forget)(struct xnthread *thread);
#ifdef CONFIG_XENO_OPT_PRIOCPL
        struct xnthread *(*sched_push_rpi)(struct xnsched *sched,
                                           struct xnthread *thread);
        void (*sched_pop_rpi)(struct xnthread *thread);
        struct xnthread *(*sched_peek_rpi)(struct xnsched *sched);
        void (*sched_suspend_rpi)(struct xnthread *thread);
        void (*sched_resume_rpi)(struct xnthread *thread);
#endif
#ifdef CONFIG_PROC_FS
        void (*sched_init_proc)(struct proc_dir_entry *root);
        void (*sched_cleanup_proc)(struct proc_dir_entry *root);
        struct proc_dir_entry *proc;
#endif
        int nthreads;
        struct xnsched_class *next;
        int weight;
        const char *name;
};

#define XNSCHED_CLASS_MAX_THREADS       32768
#define XNSCHED_CLASS_WEIGHT(n)         (n * XNSCHED_CLASS_MAX_THREADS)

/* Placeholder for current thread priority */
#define XNSCHED_RUNPRIO   0x80000000

#ifdef CONFIG_SMP
#define xnsched_cpu(__sched__)  ((__sched__)->cpu)
#else /* !CONFIG_SMP */
#define xnsched_cpu(__sched__)  ({ (void)__sched__; 0; })
#endif /* CONFIG_SMP */

/* Test resched flag of given sched. */
static inline int xnsched_resched_p(struct xnsched *sched)
{
        return testbits(sched->status, XNRESCHED);
}

/* Set self resched flag for the given scheduler. */
#define xnsched_set_self_resched(__sched__) do {                \
  XENO_BUGON(NUCLEUS, __sched__ != xnpod_current_sched());      \
  __setbits((__sched__)->status, XNRESCHED);                    \
} while (0)

/* Set resched flag for the given scheduler. */
#ifdef CONFIG_SMP
#define xnsched_set_resched(__sched__) do {                             \
  xnsched_t *current_sched = xnpod_current_sched();                     \
  if (current_sched == (__sched__))                                     \
      __setbits(current_sched->status, XNRESCHED);                      \
  else if (!xnsched_resched_p(__sched__)) {                             \
      xnarch_cpu_set(xnsched_cpu(__sched__), current_sched->resched);   \
      __setbits((__sched__)->status, XNRESCHED);                        \
      __setbits(current_sched->status, XNRESCHED);                      \
  }                                                                     \
} while (0)
#else /* !CONFIG_SMP */
#define xnsched_set_resched     xnsched_set_self_resched
#endif /* !CONFIG_SMP */

void xnsched_zombie_hooks(struct xnthread *thread);

void __xnsched_finalize_zombie(struct xnsched *sched);

static inline void xnsched_finalize_zombie(struct xnsched *sched)
{
        if (sched->zombie)
                __xnsched_finalize_zombie(sched);
}

#ifdef CONFIG_XENO_HW_UNLOCKED_SWITCH

struct xnsched *xnsched_finish_unlocked_switch(struct xnsched *sched);

#define xnsched_resched_after_unlocked_switch() xnpod_schedule()

static inline
int xnsched_maybe_resched_after_unlocked_switch(struct xnsched *sched)
{
        return testbits(sched->status, XNRESCHED);
}

#else /* !CONFIG_XENO_HW_UNLOCKED_SWITCH */

#ifdef CONFIG_SMP
#define xnsched_finish_unlocked_switch(__sched__)       \
        ({ XENO_BUGON(NUCLEUS, !irqs_disabled_hw());    \
                xnpod_current_sched(); })
#else /* !CONFIG_SMP */
#define xnsched_finish_unlocked_switch(__sched__)       \
        ({ XENO_BUGON(NUCLEUS, !irqs_disabled_hw());    \
                (__sched__); })
#endif /* !CONFIG_SMP */

#define xnsched_resched_after_unlocked_switch()         do { } while(0)

#define xnsched_maybe_resched_after_unlocked_switch(sched)      \
        ({ (void)(sched); 0; })

#endif /* !CONFIG_XENO_HW_UNLOCKED_SWITCH */

#ifdef CONFIG_XENO_OPT_WATCHDOG
static inline void xnsched_reset_watchdog(struct xnsched *sched)
{
        sched->wdcount = 0;
}
#else /* !CONFIG_XENO_OPT_WATCHDOG */
static inline void xnsched_reset_watchdog(struct xnsched *sched)
{
}
#endif /* CONFIG_XENO_OPT_WATCHDOG */

#include <nucleus/sched-idle.h>
#include <nucleus/sched-rt.h>

void xnsched_init_proc(void);

void xnsched_cleanup_proc(void);

void xnsched_register_classes(void);

void xnsched_init(struct xnsched *sched, int cpu);

void xnsched_destroy(struct xnsched *sched);

struct xnthread *xnsched_pick_next(struct xnsched *sched);

void xnsched_putback(struct xnthread *thread);

int xnsched_set_policy(struct xnthread *thread,
                       struct xnsched_class *sched_class,
                       const union xnsched_policy_param *p);

void xnsched_track_policy(struct xnthread *thread,
                          struct xnthread *target);

void xnsched_migrate(struct xnthread *thread,
                     struct xnsched *sched);

void xnsched_migrate_passive(struct xnthread *thread,
                             struct xnsched *sched);

static inline void xnsched_rotate(struct xnsched *sched,
                                  struct xnsched_class *sched_class,
                                  const union xnsched_policy_param *sched_param)
{
        sched_class->sched_rotate(sched, sched_param);
}

static inline int xnsched_init_tcb(struct xnthread *thread)
{
        int ret = 0;

        xnsched_idle_init_tcb(thread);
        xnsched_rt_init_tcb(thread);
#ifdef CONFIG_XENO_OPT_SCHED_TP
        ret = xnsched_tp_init_tcb(thread);
        if (ret)
                return ret;
#endif /* CONFIG_XENO_OPT_SCHED_TP */
#ifdef CONFIG_XENO_OPT_SCHED_SPORADIC
        ret = xnsched_sporadic_init_tcb(thread);
        if (ret)
                return ret;
#endif /* CONFIG_XENO_OPT_SCHED_SPORADIC */
        return ret;
}

static inline int xnsched_root_priority(struct xnsched *sched)
{
        return sched->rootcb.cprio;
}

static inline struct xnsched_class *xnsched_root_class(struct xnsched *sched)
{
        return sched->rootcb.sched_class;
}

static inline void xnsched_tick(struct xnthread *curr, struct xntbase *tbase)
{
        struct xnsched_class *sched_class = curr->sched_class;
        /*
         * A thread that undergoes round-robin scheduling only
         * consumes its time slice when it runs within its own
         * scheduling class, which excludes temporary PIP boosts.
         */
        if (xnthread_time_base(curr) == tbase &&
            sched_class != &xnsched_class_idle &&
            sched_class == curr->base_class &&
            xnthread_test_state(curr, XNTHREAD_BLOCK_BITS|XNLOCK|XNRRB) == XNRRB)
                sched_class->sched_tick(curr);
}

#ifdef CONFIG_XENO_OPT_SCHED_CLASSES

static inline void xnsched_enqueue(struct xnthread *thread)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class != &xnsched_class_idle)
                sched_class->sched_enqueue(thread);
}

static inline void xnsched_dequeue(struct xnthread *thread)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class != &xnsched_class_idle)
                sched_class->sched_dequeue(thread);
}

static inline void xnsched_requeue(struct xnthread *thread)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class != &xnsched_class_idle)
                sched_class->sched_requeue(thread);
}

static inline int xnsched_weighted_bprio(struct xnthread *thread)
{
        return thread->bprio + thread->sched_class->weight;
}

static inline int xnsched_weighted_cprio(struct xnthread *thread)
{
        return thread->cprio + thread->sched_class->weight;
}

static inline void xnsched_setparam(struct xnthread *thread,
                                    const union xnsched_policy_param *p)
{
        thread->sched_class->sched_setparam(thread, p);
}

static inline void xnsched_getparam(struct xnthread *thread,
                                    union xnsched_policy_param *p)
{
        thread->sched_class->sched_getparam(thread, p);
}

static inline void xnsched_trackprio(struct xnthread *thread,
                                     const union xnsched_policy_param *p)
{
        thread->sched_class->sched_trackprio(thread, p);
}

static inline void xnsched_forget(struct xnthread *thread)
{
        struct xnsched_class *sched_class = thread->base_class;

        --sched_class->nthreads;

        if (sched_class->sched_forget)
                sched_class->sched_forget(thread);
}

#ifdef CONFIG_XENO_OPT_PRIOCPL

static inline struct xnthread *xnsched_push_rpi(struct xnsched *sched,
                                                struct xnthread *thread)
{
        return thread->sched_class->sched_push_rpi(sched, thread);
}

static inline void xnsched_pop_rpi(struct xnthread *thread)
{
        thread->sched_class->sched_pop_rpi(thread);
}

static inline void xnsched_suspend_rpi(struct xnthread *thread)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class->sched_suspend_rpi)
                sched_class->sched_suspend_rpi(thread);
}

static inline void xnsched_resume_rpi(struct xnthread *thread)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class->sched_resume_rpi)
                sched_class->sched_resume_rpi(thread);
}

#endif /* CONFIG_XENO_OPT_PRIOCPL */

#else /* !CONFIG_XENO_OPT_SCHED_CLASSES */

/*
 * If only the RT and IDLE scheduling classes are compiled in, we can
 * fully inline common helpers for dealing with those.
 */

static inline void xnsched_enqueue(struct xnthread *thread)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class != &xnsched_class_idle)
                __xnsched_rt_enqueue(thread);
}

static inline void xnsched_dequeue(struct xnthread *thread)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class != &xnsched_class_idle)
                __xnsched_rt_dequeue(thread);
}

static inline void xnsched_requeue(struct xnthread *thread)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class != &xnsched_class_idle)
                __xnsched_rt_requeue(thread);
}

static inline int xnsched_weighted_bprio(struct xnthread *thread)
{
        return thread->bprio;
}

static inline int xnsched_weighted_cprio(struct xnthread *thread)
{
        return thread->cprio;
}

static inline void xnsched_setparam(struct xnthread *thread,
                                    const union xnsched_policy_param *p)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class != &xnsched_class_idle)
                __xnsched_rt_setparam(thread, p);
        else
                __xnsched_idle_setparam(thread, p);
}

static inline void xnsched_getparam(struct xnthread *thread,
                                    union xnsched_policy_param *p)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class != &xnsched_class_idle)
                __xnsched_rt_getparam(thread, p);
        else
                __xnsched_idle_getparam(thread, p);
}

static inline void xnsched_trackprio(struct xnthread *thread,
                                     const union xnsched_policy_param *p)
{
        struct xnsched_class *sched_class = thread->sched_class;

        if (sched_class != &xnsched_class_idle)
                __xnsched_rt_trackprio(thread, p);
        else
                __xnsched_idle_trackprio(thread, p);
}

static inline void xnsched_forget(struct xnthread *thread)
{
        --thread->base_class->nthreads;
        __xnsched_rt_forget(thread);
}

#ifdef CONFIG_XENO_OPT_PRIOCPL

static inline struct xnthread *xnsched_push_rpi(struct xnsched *sched,
                                                struct xnthread *thread)
{
        return __xnsched_rt_push_rpi(sched, thread);
}

static inline void xnsched_pop_rpi(struct xnthread *thread)
{
        __xnsched_rt_pop_rpi(thread);
}

static inline void xnsched_suspend_rpi(struct xnthread *thread)
{
        __xnsched_rt_suspend_rpi(thread);
}

static inline void xnsched_resume_rpi(struct xnthread *thread)
{
        __xnsched_rt_resume_rpi(thread);
}

#endif /* CONFIG_XENO_OPT_PRIOCPL */

#endif /* !CONFIG_XENO_OPT_SCHED_CLASSES */

void xnsched_renice_root(struct xnsched *sched,
                         struct xnthread *target);

struct xnthread *xnsched_peek_rpi(struct xnsched *sched);

#else /* !(__KERNEL__ || __XENO_SIM__) */

#include <nucleus/sched-idle.h>
#include <nucleus/sched-rt.h>

#endif /* !(__KERNEL__ || __XENO_SIM__) */

#endif /* !_XENO_NUCLEUS_SCHED_H */

---