fasttimer.c

linux内核源码

        if (!fast_timer_running)
        {
#ifdef FAST_TIMER_LOG
          timer_started_log[fast_timers_started % NUM_TIMER_STATS] = *t;
#endif
          start_timer1(us);
        }
        break;
      }
      else
      {
        /* Timer already expired, let's handle it better late than never.
         * The normal loop handles it
         */
        D1(printk("e! %d\n", us));
      }
    }
  }

	local_irq_restore(flags);

  if (!t)
  {
    D1(printk("t1 stop!\n"));
  }

  return IRQ_HANDLED;
}

static void wake_up_func(unsigned long data)
{
#ifdef DECLARE_WAITQUEUE
  wait_queue_head_t  *sleep_wait_p = (wait_queue_head_t*)data;
#else
  struct wait_queue **sleep_wait_p = (struct wait_queue **)data;
#endif
  wake_up(sleep_wait_p);
}


/* Useful API */

void schedule_usleep(unsigned long us)
{
  struct fast_timer t;
  wait_queue_head_t sleep_wait;
  init_waitqueue_head(&sleep_wait);

  D1(printk("schedule_usleep(%d)\n", us));
  start_one_shot_timer(&t, wake_up_func, (unsigned long)&sleep_wait, us,
                       "usleep");
	/* Uninterruptible sleep on the fast timer. (The condition is somewhat
	 * redundant since the timer is what wakes us up.) */
	wait_event(sleep_wait, !fast_timer_pending(&t));

  D1(printk("done schedule_usleep(%d)\n", us));
}

#ifdef CONFIG_PROC_FS
static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
                       ,int *eof, void *data_unused);
static struct proc_dir_entry *fasttimer_proc_entry;
#endif /* CONFIG_PROC_FS */

#ifdef CONFIG_PROC_FS

/* This value is very much based on testing */
#define BIG_BUF_SIZE (500 + NUM_TIMER_STATS * 300)

static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
                       ,int *eof, void *data_unused)
{
  unsigned long flags;
  int i = 0;
  int num_to_show;
	struct fasttime_t tv;
  struct fast_timer *t, *nextt;
  static char *bigbuf = NULL;
  static unsigned long used;

  if (!bigbuf && !(bigbuf = vmalloc(BIG_BUF_SIZE)))
  {
    used = 0;
	if (buf)
		buf[0] = '\0';
    return 0;
  }

  if (!offset || !used)
  {
    do_gettimeofday_fast(&tv);

    used = 0;
    used += sprintf(bigbuf + used, "Fast timers added:     %i\n",
                    fast_timers_added);
    used += sprintf(bigbuf + used, "Fast timers started:   %i\n",
                    fast_timers_started);
    used += sprintf(bigbuf + used, "Fast timer interrupts: %i\n",
                    fast_timer_ints);
    used += sprintf(bigbuf + used, "Fast timers expired:   %i\n",
                    fast_timers_expired);
    used += sprintf(bigbuf + used, "Fast timers deleted:   %i\n",
                    fast_timers_deleted);
    used += sprintf(bigbuf + used, "Fast timer running:    %s\n",
                    fast_timer_running ? "yes" : "no");
    used += sprintf(bigbuf + used, "Current time:          %lu.%06lu\n",
			(unsigned long)tv.tv_jiff,
                    (unsigned long)tv.tv_usec);
#ifdef FAST_TIMER_SANITY_CHECKS
    used += sprintf(bigbuf + used, "Sanity failed:         %i\n",
                    sanity_failed);
#endif
    used += sprintf(bigbuf + used, "\n");

#ifdef DEBUG_LOG_INCLUDED
    {
      int end_i = debug_log_cnt;
      i = 0;

      if (debug_log_cnt_wrapped)
      {
        i = debug_log_cnt;
      }

      while ((i != end_i || (debug_log_cnt_wrapped && !used)) &&
             used+100 < BIG_BUF_SIZE)
      {
        used += sprintf(bigbuf + used, debug_log_string[i],
                        debug_log_value[i]);
        i = (i+1) % DEBUG_LOG_MAX;
      }
    }
    used += sprintf(bigbuf + used, "\n");
#endif

    num_to_show = (fast_timers_started < NUM_TIMER_STATS ? fast_timers_started:
                   NUM_TIMER_STATS);
    used += sprintf(bigbuf + used, "Timers started: %i\n", fast_timers_started);
    for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE) ; i++)
    {
      int cur = (fast_timers_started - i - 1) % NUM_TIMER_STATS;

#if 1 //ndef FAST_TIMER_LOG
      used += sprintf(bigbuf + used, "div: %i freq: %i delay: %i"
                      "\n",
                      timer_div_settings[cur],
                      timer_freq_settings[cur],
                      timer_delay_settings[cur]
                      );
#endif
#ifdef FAST_TIMER_LOG
      t = &timer_started_log[cur];
      used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
                      "d: %6li us data: 0x%08lX"
                      "\n",
                      t->name,
			(unsigned long)t->tv_set.tv_jiff,
                      (unsigned long)t->tv_set.tv_usec,
			(unsigned long)t->tv_expires.tv_jiff,
                      (unsigned long)t->tv_expires.tv_usec,
                      t->delay_us,
                      t->data
                      );
#endif
    }
    used += sprintf(bigbuf + used, "\n");

#ifdef FAST_TIMER_LOG
    num_to_show = (fast_timers_added < NUM_TIMER_STATS ? fast_timers_added:
                   NUM_TIMER_STATS);
    used += sprintf(bigbuf + used, "Timers added: %i\n", fast_timers_added);
    for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE); i++)
    {
      t = &timer_added_log[(fast_timers_added - i - 1) % NUM_TIMER_STATS];
      used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
                      "d: %6li us data: 0x%08lX"
                      "\n",
                      t->name,
			(unsigned long)t->tv_set.tv_jiff,
                      (unsigned long)t->tv_set.tv_usec,
			(unsigned long)t->tv_expires.tv_jiff,
                      (unsigned long)t->tv_expires.tv_usec,
                      t->delay_us,
                      t->data
                      );
    }
    used += sprintf(bigbuf + used, "\n");

    num_to_show = (fast_timers_expired < NUM_TIMER_STATS ? fast_timers_expired:
                   NUM_TIMER_STATS);
    used += sprintf(bigbuf + used, "Timers expired: %i\n", fast_timers_expired);
    for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE); i++)
    {
      t = &timer_expired_log[(fast_timers_expired - i - 1) % NUM_TIMER_STATS];
      used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
                      "d: %6li us data: 0x%08lX"
                      "\n",
                      t->name,
			(unsigned long)t->tv_set.tv_jiff,
                      (unsigned long)t->tv_set.tv_usec,
			(unsigned long)t->tv_expires.tv_jiff,
                      (unsigned long)t->tv_expires.tv_usec,
                      t->delay_us,
                      t->data
                      );
    }
    used += sprintf(bigbuf + used, "\n");
#endif

    used += sprintf(bigbuf + used, "Active timers:\n");
    local_irq_save(flags);
    t = fast_timer_list;
    while (t != NULL && (used+100 < BIG_BUF_SIZE))
    {
      nextt = t->next;
      local_irq_restore(flags);
      used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
                      "d: %6li us data: 0x%08lX"
/*                      " func: 0x%08lX" */
                      "\n",
                      t->name,
			(unsigned long)t->tv_set.tv_jiff,
                      (unsigned long)t->tv_set.tv_usec,
			(unsigned long)t->tv_expires.tv_jiff,
                      (unsigned long)t->tv_expires.tv_usec,
                      t->delay_us,
                      t->data
/*                      , t->function */
                      );
	local_irq_save(flags);
      if (t->next != nextt)
      {
        printk(KERN_WARNING "timer removed!\n");
      }
      t = nextt;
    }
    local_irq_restore(flags);
  }

  if (used - offset < len)
  {
    len = used - offset;
  }

  memcpy(buf, bigbuf + offset, len);
  *start = buf;
  *eof = 1;

  return len;
}
#endif /* PROC_FS */

#ifdef FAST_TIMER_TEST
static volatile unsigned long i = 0;
static volatile int num_test_timeout = 0;
static struct fast_timer tr[10];
static int exp_num[10];

static struct fasttime_t tv_exp[100];

static void test_timeout(unsigned long data)
{
  do_gettimeofday_fast(&tv_exp[data]);
  exp_num[data] = num_test_timeout;

  num_test_timeout++;
}

static void test_timeout1(unsigned long data)
{
  do_gettimeofday_fast(&tv_exp[data]);
  exp_num[data] = num_test_timeout;
  if (data < 7)
  {
    start_one_shot_timer(&tr[i], test_timeout1, i, 1000, "timeout1");
    i++;
  }
  num_test_timeout++;
}

DP(
static char buf0[2000];
static char buf1[2000];
static char buf2[2000];
static char buf3[2000];
static char buf4[2000];
);

static char buf5[6000];
static int j_u[1000];

static void fast_timer_test(void)
{
  int prev_num;
  int j;

	struct fasttime_t tv, tv0, tv1, tv2;

  printk("fast_timer_test() start\n");
  do_gettimeofday_fast(&tv);

  for (j = 0; j < 1000; j++)
  {
    j_u[j] = GET_JIFFIES_USEC();
  }
  for (j = 0; j < 100; j++)
  {
    do_gettimeofday_fast(&tv_exp[j]);
  }
	printk(KERN_DEBUG "fast_timer_test() %is %06i\n",
		tv.tv_jiff, tv.tv_usec);

  for (j = 0; j < 1000; j++)
  {
    printk("%i %i %i %i %i\n",j_u[j], j_u[j+1], j_u[j+2], j_u[j+3], j_u[j+4]);
    j += 4;
  }
  for (j = 0; j < 100; j++)
  {
		printk(KERN_DEBUG "%i.%i %i.%i %i.%i %i.%i %i.%i\n",
			tv_exp[j].tv_jiff, tv_exp[j].tv_usec,
			tv_exp[j+1].tv_jiff, tv_exp[j+1].tv_usec,
			tv_exp[j+2].tv_jiff, tv_exp[j+2].tv_usec,
			tv_exp[j+3].tv_jiff, tv_exp[j+3].tv_usec,
			tv_exp[j+4].tv_jiff, tv_exp[j+4].tv_usec);
    j += 4;
  }
  do_gettimeofday_fast(&tv0);
  start_one_shot_timer(&tr[i], test_timeout, i, 50000, "test0");
  DP(proc_fasttimer_read(buf0, NULL, 0, 0, 0));
  i++;
  start_one_shot_timer(&tr[i], test_timeout, i, 70000, "test1");
  DP(proc_fasttimer_read(buf1, NULL, 0, 0, 0));
  i++;
  start_one_shot_timer(&tr[i], test_timeout, i, 40000, "test2");
  DP(proc_fasttimer_read(buf2, NULL, 0, 0, 0));
  i++;
  start_one_shot_timer(&tr[i], test_timeout, i, 60000, "test3");
  DP(proc_fasttimer_read(buf3, NULL, 0, 0, 0));
  i++;
  start_one_shot_timer(&tr[i], test_timeout1, i, 55000, "test4xx");
  DP(proc_fasttimer_read(buf4, NULL, 0, 0, 0));
  i++;
  do_gettimeofday_fast(&tv1);

  proc_fasttimer_read(buf5, NULL, 0, 0, 0);

  prev_num = num_test_timeout;
  while (num_test_timeout < i)
  {
    if (num_test_timeout != prev_num)
    {
      prev_num = num_test_timeout;
    }
  }
  do_gettimeofday_fast(&tv2);
	printk(KERN_DEBUG "Timers started    %is %06i\n",
		tv0.tv_jiff, tv0.tv_usec);
	printk(KERN_DEBUG "Timers started at %is %06i\n",
		tv1.tv_jiff, tv1.tv_usec);
	printk(KERN_DEBUG "Timers done       %is %06i\n",
		tv2.tv_jiff, tv2.tv_usec);
  DP(printk("buf0:\n");
     printk(buf0);
     printk("buf1:\n");
     printk(buf1);
     printk("buf2:\n");
     printk(buf2);
     printk("buf3:\n");
     printk(buf3);
     printk("buf4:\n");
     printk(buf4);
  );
  printk("buf5:\n");
  printk(buf5);

  printk("timers set:\n");
  for(j = 0; j<i; j++)
  {
    struct fast_timer *t = &tr[j];
    printk("%-10s set: %6is %06ius exp: %6is %06ius "
           "data: 0x%08X func: 0x%08X\n",
           t->name,
			t->tv_set.tv_jiff,
           t->tv_set.tv_usec,
			t->tv_expires.tv_jiff,
           t->tv_expires.tv_usec,
           t->data,
           t->function
           );

    printk("           del: %6ius     did exp: %6is %06ius as #%i error: %6li\n",
           t->delay_us,
			tv_exp[j].tv_jiff,
           tv_exp[j].tv_usec,
           exp_num[j],
			(tv_exp[j].tv_jiff - t->tv_expires.tv_jiff) *
				1000000 + tv_exp[j].tv_usec -
				t->tv_expires.tv_usec);
  }
  proc_fasttimer_read(buf5, NULL, 0, 0, 0);
  printk("buf5 after all done:\n");
  printk(buf5);
  printk("fast_timer_test() done\n");
}
#endif


int fast_timer_init(void)
{
  /* For some reason, request_irq() hangs when called froom time_init() */
  if (!fast_timer_is_init)
  {
#if 0 && defined(FAST_TIMER_TEST)
    int i;
#endif

    printk(KERN_INFO "fast_timer_init()\n");

#if 0 && defined(FAST_TIMER_TEST)
    for (i = 0; i <= TIMER0_DIV; i++)
    {
      /* We must be careful not to get overflow... */
      printk("%3i %6u\n", i, timer0_value_us[i]);
    }
#endif
#ifdef CONFIG_PROC_FS
   if ((fasttimer_proc_entry = create_proc_entry( "fasttimer", 0, 0 )))
     fasttimer_proc_entry->read_proc = proc_fasttimer_read;
#endif /* PROC_FS */
    if(request_irq(TIMER1_IRQ_NBR, timer1_handler, 0,
                   "fast timer int", NULL))
    {
      printk("err: timer1 irq\n");
    }
    fast_timer_is_init = 1;
#ifdef FAST_TIMER_TEST
    printk("do test\n");
    fast_timer_test();
#endif
  }
	return 0;
}
__initcall(fast_timer_init);