C++ profile_tick函数代码示例

static irqreturn_t timer_interrupt(int dummy, void *dev_id)
{
	/* last time the cmos clock got updated */
	static long last_rtc_update;

#ifndef CONFIG_SMP
	profile_tick(CPU_PROFILING);
#endif

	/* Protect counter clear so that do_gettimeoffset works */
	write_seqlock(&xtime_lock);

	clear_clock_irq();

	do_timer(1);

	/* Determine when to update the Mostek clock. */
	if (ntp_synced() &&
	    xtime.tv_sec > last_rtc_update + 660 &&
	    (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
	    (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
	  if (set_rtc_mmss(xtime.tv_sec) == 0)
	    last_rtc_update = xtime.tv_sec;
	  else
	    last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
	}
	write_sequnlock(&xtime_lock);

#ifndef CONFIG_SMP
	update_process_times(user_mode(get_irq_regs()));
#endif
	return IRQ_HANDLED;
}

/*
 * timer_interrupt() needs to keep up the real-time clock,
 * as well as call the "do_timer()" routine every clocktick
 */
static irqreturn_t timer_interrupt(int irq, void *dummy)
{
	do_timer(1);
#ifndef CONFIG_SMP
	update_process_times(user_mode(get_irq_regs()));
#endif
	profile_tick(CPU_PROFILING);

#ifdef CONFIG_HEARTBEAT
	/* use power LED as a heartbeat instead -- much more useful
	   for debugging -- based on the version for PReP by Cort */
	/* acts like an actual heart beat -- ie thump-thump-pause... */
	if (mach_heartbeat) {
	    static unsigned cnt = 0, period = 0, dist = 0;

	    if (cnt == 0 || cnt == dist)
		mach_heartbeat( 1 );
	    else if (cnt == 7 || cnt == dist+7)
		mach_heartbeat( 0 );

	    if (++cnt > period) {
		cnt = 0;
		/* The hyperbolic function below modifies the heartbeat period
		 * length in dependency of the current (5min) load. It goes
		 * through the points f(0)=126, f(1)=86, f(5)=51,
		 * f(inf)->30. */
		period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
		dist = period / 4;
	    }
	}
#endif /* CONFIG_HEARTBEAT */
	return IRQ_HANDLED;
}

irqreturn_t timer_interrupt (int irq, void *dev_id)
{

	unsigned long next;

	next = get_linux_timer();

again:
	while ((signed long)(get_ccount() - next) > 0) {

		profile_tick(CPU_PROFILING);
#ifndef CONFIG_SMP
		update_process_times(user_mode(get_irq_regs()));
#endif

		xtime_update(1); /*                                          */

		/*                                                  */

		next += CCOUNT_PER_JIFFY;
		set_linux_timer(next);
	}

	/*                                               */

	platform_heartbeat();

	/*                                      */

	if ((signed long)(get_ccount() - next) > 0)
		goto again;

	return IRQ_HANDLED;
}

/*
 * timer_interrupt() needs to keep up the real-time clock,
 * as well as call the "do_timer()" routine every clocktick
 */
static inline void
do_timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
#ifndef CONFIG_SMP
	profile_tick(CPU_PROFILING, regs);
#endif
	do_timer(regs);

#ifndef CONFIG_SMP
	update_process_times(user_mode(regs));
#endif
	/*
	 * If we have an externally synchronized Linux clock, then update
	 * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
	 * called as close as possible to 500 ms before the new second starts.
	 */
	if ((time_status & STA_UNSYNC) == 0
		&& xtime.tv_sec > last_rtc_update + 660
		&& (xtime.tv_nsec / 1000) >= 500000 - ((unsigned)TICK_SIZE) / 2
		&& (xtime.tv_nsec / 1000) <= 500000 + ((unsigned)TICK_SIZE) / 2)
	{
		if (set_rtc_mmss(xtime.tv_sec) == 0)
			last_rtc_update = xtime.tv_sec;
		else	/* do it again in 60 s */
			last_rtc_update = xtime.tv_sec - 600;
	}
	/* As we return to user mode fire off the other CPU schedulers..
	   this is basically because we don't yet share IRQ's around.
	   This message is rigged to be safe on the 386 - basically it's
	   a hack, so don't look closely for now.. */

#ifdef CONFIG_SMP
	smp_local_timer_interrupt(regs);
#endif
}

static void tick_nohz_handler(struct clock_event_device *dev)
{
	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
	struct pt_regs *regs = get_irq_regs();
	int cpu = smp_processor_id();
	ktime_t now = ktime_get();

	dev->next_event.tv64 = KTIME_MAX;

	if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE))
		tick_do_timer_cpu = cpu;

	
	if (tick_do_timer_cpu == cpu)
		tick_do_update_jiffies64(now);

	if (ts->tick_stopped) {
		touch_softlockup_watchdog();
		ts->idle_jiffies++;
	}

	update_process_times(user_mode(regs));
	profile_tick(CPU_PROFILING);

	while (tick_nohz_reprogram(ts, now)) {
		now = ktime_get();
		tick_do_update_jiffies64(now);
	}
}

void coldfire_profile_tick(int irq, void *dummy, struct pt_regs *regs)
{
	/* Reset ColdFire timer2 */
	mcf_proftp->ter = MCFTIMER_TER_CAP | MCFTIMER_TER_REF;
	if (current->pid)
		profile_tick(CPU_PROFILING, regs);
}

/*==========================================================================*
 * Name:         smp_local_timer_interrupt
 *
 * Description:  Local timer interrupt handler. It does both profiling and
 *               process statistics/rescheduling.
 *               We do profiling in every local tick, statistics/rescheduling
 *               happen only every 'profiling multiplier' ticks. The default
 *               multiplier is 1 and it can be changed by writing the new
 *               multiplier value into /proc/profile.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    *regs - a pointer to the saved regster info
 *
 * Returns:      void (cannot fail)
 *
 * Original:     arch/i386/kernel/apic.c
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 * 2003-06-24 hy  use per_cpu structure.
 *==========================================================================*/
void smp_local_timer_interrupt(void)
{
	int user = user_mode(get_irq_regs());
	int cpu_id = smp_processor_id();

	/*
	 * The profiling function is SMP safe. (nothing can mess
	 * around with "current", and the profiling counters are
	 * updated with atomic operations). This is especially
	 * useful with a profiling multiplier != 1
	 */

	profile_tick(CPU_PROFILING);

	if (--per_cpu(prof_counter, cpu_id) <= 0) {
		/*
		 * The multiplier may have changed since the last time we got
		 * to this point as a result of the user writing to
		 * /proc/profile. In this case we need to adjust the APIC
		 * timer accordingly.
		 *
		 * Interrupts are already masked off at this point.
		 */
		per_cpu(prof_counter, cpu_id)
			= per_cpu(prof_multiplier, cpu_id);
		if (per_cpu(prof_counter, cpu_id)
			!= per_cpu(prof_old_multiplier, cpu_id))
		{
			per_cpu(prof_old_multiplier, cpu_id)
				= per_cpu(prof_counter, cpu_id);
		}

		update_process_times(user);
	}
}

static irqreturn_t timer_interrupt(int dummy, void *dev_id)
{
#ifndef CONFIG_SMP
	profile_tick(CPU_PROFILING);
#endif

<<<<<<< HEAD

/*
 * timer_interrupt() needs to keep up the real-time clock,
 * as well as call the "do_timer()" routine every clocktick
 */
static irqreturn_t timer_interrupt(int irq, void *dummy)
{
	profile_tick(CPU_PROFILING);
	/*
	 * Here we are in the timer irq handler. We just have irqs locally
	 * disabled but we don't know if the timer_bh is running on the other
	 * CPU. We need to avoid to SMP race with it. NOTE: we don't need
	 * the irq version of write_lock because as just said we have irq
	 * locally disabled. -arca
	 */
	write_seqlock(&xtime_lock);

	do_timer(1);

#ifdef CONFIG_HEARTBEAT
	static unsigned short n;
	n++;
	__set_LEDS(n);
#endif /* CONFIG_HEARTBEAT */

	write_sequnlock(&xtime_lock);

	update_process_times(user_mode(get_irq_regs()));

	return IRQ_HANDLED;
}

/*
 * handle_timer_tick() needs to keep up the real-time clock,
 * as well as call the "do_timer()" routine every clocktick
 */
void handle_timer_tick(struct pt_regs *regs)
{
	do_timer(regs);
#ifndef CONFIG_SMP
	update_process_times(user_mode(regs));
#endif
	profile_tick(CPU_PROFILING, regs);

#ifdef CONFIG_HEARTBEAT
	if (sh_mv.mv_heartbeat != NULL)
		sh_mv.mv_heartbeat();
#endif

	/*
	 * If we have an externally synchronized Linux clock, then update
	 * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
	 * called as close as possible to 500 ms before the new second starts.
	 */
	if (ntp_synced() &&
	    xtime.tv_sec > last_rtc_update + 660 &&
	    (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
	    (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
		if (rtc_set_time(xtime.tv_sec) == 0)
			last_rtc_update = xtime.tv_sec;
		else
			/* do it again in 60s */
			last_rtc_update = xtime.tv_sec - 600;
	}
}

static irqreturn_t timer_interrupt(int irq, void *dummy)
{
	xtime_update(1);
	update_process_times(user_mode(get_irq_regs()));
	profile_tick(CPU_PROFILING);

#ifdef CONFIG_HEARTBEAT
	/*                                                         
                                                           */
	/*                                                           */
	if (mach_heartbeat) {
	    static unsigned cnt = 0, period = 0, dist = 0;

	    if (cnt == 0 || cnt == dist)
		mach_heartbeat( 1 );
	    else if (cnt == 7 || cnt == dist+7)
		mach_heartbeat( 0 );

	    if (++cnt > period) {
		cnt = 0;
		/*                                                            
                                                             
                                                   
                 */
		period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
		dist = period / 4;
	    }
	}
#endif /*                  */
	return IRQ_HANDLED;
}

static irqreturn_t
timer_interrupt (int irq, void *dev_id, struct pt_regs *regs)
{
    unsigned long new_itm;

    if (unlikely(cpu_is_offline(smp_processor_id()))) {
        return IRQ_HANDLED;
    }

    platform_timer_interrupt(irq, dev_id, regs);

    new_itm = local_cpu_data->itm_next;

    if (!time_after(ia64_get_itc(), new_itm))
        printk(KERN_ERR "Oops: timer tick before it's due (itc=%lx,itm=%lx)\n",
               ia64_get_itc(), new_itm);

    profile_tick(CPU_PROFILING, regs);

    while (1) {
        update_process_times(user_mode(regs));

        new_itm += local_cpu_data->itm_delta;

        if (smp_processor_id() == TIME_KEEPER_ID) {
            /*
             * Here we are in the timer irq handler. We have irqs locally
             * disabled, but we don't know if the timer_bh is running on
             * another CPU. We need to avoid to SMP race by acquiring the
             * xtime_lock.
             */
            write_seqlock(&xtime_lock);
            do_timer(regs);
            local_cpu_data->itm_next = new_itm;
            write_sequnlock(&xtime_lock);
        } else
            local_cpu_data->itm_next = new_itm;

        if (time_after(new_itm, ia64_get_itc()))
            break;
    }

    do {
        /*
         * If we're too close to the next clock tick for
         * comfort, we increase the safety margin by
         * intentionally dropping the next tick(s).  We do NOT
         * update itm.next because that would force us to call
         * do_timer() which in turn would let our clock run
         * too fast (with the potentially devastating effect
         * of losing monotony of time).
         */
        while (!time_after(new_itm, ia64_get_itc() + local_cpu_data->itm_delta/2))
            new_itm += local_cpu_data->itm_delta;
        ia64_set_itm(new_itm);
        /* double check, in case we got hit by a (slow) PMI: */
    } while (time_after_eq(ia64_get_itc(), new_itm));
    return IRQ_HANDLED;
}

/*
 * We keep time on PA-RISC Linux by using the Interval Timer which is
 * a pair of registers; one is read-only and one is write-only; both
 * accessed through CR16.  The read-only register is 32 or 64 bits wide,
 * and increments by 1 every CPU clock tick.  The architecture only
 * guarantees us a rate between 0.5 and 2, but all implementations use a
 * rate of 1.  The write-only register is 32-bits wide.  When the lowest
 * 32 bits of the read-only register compare equal to the write-only
 * register, it raises a maskable external interrupt.  Each processor has
 * an Interval Timer of its own and they are not synchronised.  
 *
 * We want to generate an interrupt every 1/HZ seconds.  So we program
 * CR16 to interrupt every @clocktick cycles.  The it_value in cpu_data
 * is programmed with the intended time of the next tick.  We can be
 * held off for an arbitrarily long period of time by interrupts being
 * disabled, so we may miss one or more ticks.
 */
irqreturn_t __irq_entry timer_interrupt(int irq, void *dev_id)
{
	unsigned long now;
	unsigned long next_tick;
	unsigned long ticks_elapsed = 0;
	unsigned int cpu = smp_processor_id();
	struct cpuinfo_parisc *cpuinfo = &per_cpu(cpu_data, cpu);

	/* gcc can optimize for "read-only" case with a local clocktick */
	unsigned long cpt = clocktick;

	profile_tick(CPU_PROFILING);

	/* Initialize next_tick to the old expected tick time. */
	next_tick = cpuinfo->it_value;

	/* Calculate how many ticks have elapsed. */
	do {
		++ticks_elapsed;
		next_tick += cpt;
		now = mfctl(16);
	} while (next_tick - now > cpt);

	/* Store (in CR16 cycles) up to when we are accounting right now. */
	cpuinfo->it_value = next_tick;

	/* Go do system house keeping. */
	if (cpu == 0)
		xtime_update(ticks_elapsed);

	update_process_times(user_mode(get_irq_regs()));

	/* Skip clockticks on purpose if we know we would miss those.
	 * The new CR16 must be "later" than current CR16 otherwise
	 * itimer would not fire until CR16 wrapped - e.g 4 seconds
	 * later on a 1Ghz processor. We'll account for the missed
	 * ticks on the next timer interrupt.
	 * We want IT to fire modulo clocktick even if we miss/skip some.
	 * But those interrupts don't in fact get delivered that regularly.
	 *
	 * "next_tick - now" will always give the difference regardless
	 * if one or the other wrapped. If "now" is "bigger" we'll end up
	 * with a very large unsigned number.
	 */
	while (next_tick - mfctl(16) > cpt)
		next_tick += cpt;

	/* Program the IT when to deliver the next interrupt.
	 * Only bottom 32-bits of next_tick are writable in CR16!
	 * Timer interrupt will be delivered at least a few hundred cycles
	 * after the IT fires, so if we are too close (<= 500 cycles) to the
	 * next cycle, simply skip it.
	 */
	if (next_tick - mfctl(16) <= 500)
		next_tick += cpt;
	mtctl(next_tick, 16);

	return IRQ_HANDLED;
}

/*
 * timer_interrupt() needs to keep up the real-time clock,
 * as well as call the "do_timer()" routine every clocktick
 */
static irqreturn_t timer_interrupt(int irq, void *dummy)
{
	/* last time the cmos clock got updated */
	static long last_rtc_update=0;

	/* may need to kick the hardware timer */
	if (mach_tick)
	  mach_tick();

	write_seqlock(&xtime_lock);

	do_timer(1);
#ifndef CONFIG_SMP
	update_process_times(user_mode(get_irq_regs()));
#endif
	if (current->pid)
		profile_tick(CPU_PROFILING);

	/*
	 * If we have an externally synchronized Linux clock, then update
	 * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
	 * called as close as possible to 500 ms before the new second starts.
	 */
	if (ntp_synced() &&
	    xtime.tv_sec > last_rtc_update + 660 &&
	    (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
	    (xtime.tv_nsec  / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
	  if (set_rtc_mmss(xtime.tv_sec) == 0)
	    last_rtc_update = xtime.tv_sec;
	  else
	    last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
	}
#ifdef CONFIG_HEARTBEAT
	/* use power LED as a heartbeat instead -- much more useful
	   for debugging -- based on the version for PReP by Cort */
	/* acts like an actual heart beat -- ie thump-thump-pause... */
	if (mach_heartbeat) {
	    static unsigned cnt = 0, period = 0, dist = 0;

	    if (cnt == 0 || cnt == dist)
		mach_heartbeat( 1 );
	    else if (cnt == 7 || cnt == dist+7)
		mach_heartbeat( 0 );

	    if (++cnt > period) {
		cnt = 0;
		/* The hyperbolic function below modifies the heartbeat period
		 * length in dependency of the current (5min) load. It goes
		 * through the points f(0)=126, f(1)=86, f(5)=51,
		 * f(inf)->30. */
		period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
		dist = period / 4;
	    }
	}
#endif /* CONFIG_HEARTBEAT */

	write_sequnlock(&xtime_lock);
	return(IRQ_HANDLED);
}

irqreturn_t mcfslt_profile_tick(int irq, void *dummy)
{
	/* Reset Slice Timer 1 */
	__raw_writel(MCFSLT_SSR_BE | MCFSLT_SSR_TE, PA(MCFSLT_SSR));
	if (current->pid)
		profile_tick(CPU_PROFILING);
	return IRQ_HANDLED;
}