tests/kernel/test-spinlock.c

   1 /* test-cmpxchg.c
   2  *
   3  * Test time spent in a LTTng instrumentation probe.
   4  */
   5
   6
   7 #include <linux/jiffies.h>
   8 #include <linux/compiler.h>
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 #include <linux/spinlock.h>
  12
  13 #define NR_LOOPS 20000
  14
  15 volatile int test_val = 100;
  16
  17 spinlock_t lock = SPIN_LOCK_UNLOCKED;
  18
  19 static inline void do_test(void)
  20 {
  21         unsigned long flags;
  22
  23         spin_lock_irqsave(&lock, flags);
  24         test_val += 1;
  25         spin_unlock_irqrestore(&lock, flags);
  26 }
  27
  28 //void (*fct)(void) = do_test;
  29
  30 static int ltt_test_init(void)
  31 {
  32         unsigned int i;
  33         cycles_t time1, time2, time;
  34         cycles_t max_time = 0, min_time = 18446744073709551615ULL; /* (2^64)-1 */
  35         cycles_t tot_time = 0;
  36         unsigned long flags;
  37         printk(KERN_ALERT "test init\n");
  38
  39         local_irq_save(flags);
  40         time1 = get_cycles();
  41         for(i=0; i<NR_LOOPS; i++) {
  42                 //for(int j=0; j<10; j++) {
  43                 do_test();
  44                 //}
  45                 //max_time = max(max_time, time);
  46                 //min_time = min(min_time, time);
  47                 //printk("val : %d\n", test_val);
  48         }
  49         time2 = get_cycles();
  50         local_irq_restore(flags);
  51         time = time2 - time1;
  52         tot_time += time;
  53
  54         printk(KERN_ALERT "test results : time for spinlock irqsave\n");
  55         printk(KERN_ALERT "number of loops : %d\n", NR_LOOPS);
  56         printk(KERN_ALERT "total time : %llu\n", tot_time);
  57         //printk(KERN_ALERT "min : %llu\n", min_time);
  58         //printk(KERN_ALERT "max : %llu\n", max_time);
  59
  60         printk(KERN_ALERT "test end\n");
  61
  62         return -EAGAIN; /* Fail will directly unload the module */
  63 }
  64
  65 static void ltt_test_exit(void)
  66 {
  67         printk(KERN_ALERT "test exit\n");
  68 }
  69
  70 module_init(ltt_test_init)
  71 module_exit(ltt_test_exit)
  72
  73 MODULE_LICENSE("GPL");
  74 MODULE_AUTHOR("Mathieu Desnoyers");
  75 MODULE_DESCRIPTION("Linux Trace Toolkit Test");
  76