tests/kernel/test-irqloop.c

   1 /* test-irqloop
   2  *
   3  * Test time spent for irq disabling
   4  */
   5
   6
   7 #include <linux/config.h>
   8 #include <linux/jiffies.h>
   9 #include <linux/compiler.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12
  13 #define NR_LOOPS 20000
  14
  15 static int ltt_test_init(void)
  16 {
  17         unsigned int i;
  18         cycles_t time1, time2, time;
  19         cycles_t max_time = 0, min_time = 18446744073709551615ULL; /* (2^64)-1 */
  20         cycles_t tot_time = 0;
  21         unsigned long flags;
  22         printk(KERN_ALERT "test init\n");
  23
  24         time1 = get_cycles();
  25         for(i=0; i<NR_LOOPS; i++) {
  26                 local_irq_save(flags);
  27                 local_irq_restore(flags);
  28         }
  29         time2 = get_cycles();
  30         time = time2 - time1;
  31         tot_time += time;
  32
  33         printk(KERN_ALERT "test results : time for irq save/restore\n");
  34         printk(KERN_ALERT "number of loops : %d\n", NR_LOOPS);
  35         printk(KERN_ALERT "total time : %llu\n", tot_time);
  36         //printk(KERN_ALERT "min : %llu\n", min_time);
  37         //printk(KERN_ALERT "max : %llu\n", max_time);
  38
  39         printk(KERN_ALERT "test end\n");
  40
  41         return -EAGAIN; /* Fail will directly unload the module */
  42 }
  43
  44 static void ltt_test_exit(void)
  45 {
  46         printk(KERN_ALERT "test exit\n");
  47 }
  48
  49 module_init(ltt_test_init)
  50 module_exit(ltt_test_exit)
  51
  52 MODULE_LICENSE("GPL");
  53 MODULE_AUTHOR("Mathieu Desnoyers");
  54 MODULE_DESCRIPTION("Linux Trace Toolkit Test");
  55