trunk/tests/kernel/test-nop-speed.c

   1 /* test-nop-speed.c
   2  *
   3  */
   4
   5 #include <linux/module.h>
   6 #include <linux/proc_fs.h>
   7 #include <linux/sched.h>
   8 #include <linux/timex.h>
   9 #include <linux/marker.h>
  10 #include <asm/ptrace.h>
  11
  12 #define NR_TESTS 20000
  13
  14 struct proc_dir_entry *pentry = NULL;
  15
  16 void empty(void)
  17 {
  18         asm volatile ("");
  19 }
  20
  21 void twobytesjump(void)
  22 {
  23         asm volatile ("jmp 1f\n\t"
  24                 ".byte 0x00, 0x00, 0x00\n\t"
  25                 "1:\n\t");
  26 }
  27
  28 void fivebytesjump(void)
  29 {
  30         asm (".byte 0xe9, 0x00, 0x00, 0x00, 0x00\n\t");
  31 }
  32
  33 void threetwonops(void)
  34 {
  35         asm (".byte 0x66,0x66,0x90,0x66,0x90\n\t");
  36 }
  37
  38 void fivebytesnop(void)
  39 {
  40         asm (".byte 0x66,0x66,0x66,0x66,0x90\n\t");
  41 }
  42
  43 void fivebytespsixnop(void)
  44 {
  45         asm (".byte 0x0f,0x1f,0x44,0x00,0\n\t");
  46 }
  47
  48 void perform_test(const char *name, void (*callback)(void))
  49 {
  50         unsigned int i;
  51         cycles_t cycles1, cycles2;
  52         unsigned long flags;
  53
  54         local_irq_save(flags);
  55         rdtsc_barrier();
  56         cycles1 = get_cycles();
  57         rdtsc_barrier();
  58         for(i=0; i<NR_TESTS; i++) {
  59                 callback();
  60         }
  61         rdtsc_barrier();
  62         cycles2 = get_cycles();
  63         rdtsc_barrier();
  64         local_irq_restore(flags);
  65         printk("test %s cycles : %llu\n", name, cycles2-cycles1);
  66 }
  67
  68 static int my_open(struct inode *inode, struct file *file)
  69 {
  70         printk("NR_TESTS %d\n", NR_TESTS);
  71
  72         perform_test("empty", empty);
  73         perform_test("2-bytes jump", twobytesjump);
  74         perform_test("5-bytes jump", fivebytesjump);
  75         perform_test("3/2 nops", threetwonops);
  76         perform_test("5-bytes nop with long prefix", fivebytesnop);
  77         perform_test("5-bytes P6 nop", fivebytespsixnop);
  78
  79         return -EPERM;
  80 }
  81
  82
  83 static struct file_operations my_operations = {
  84         .open = my_open,
  85 };
  86
  87 int init_module(void)
  88 {
  89         pentry = create_proc_entry("testnops", 0444, NULL);
  90         if (pentry)
  91                 pentry->proc_fops = &my_operations;
  92
  93         return 0;
  94 }
  95
  96 void cleanup_module(void)
  97 {
  98         remove_proc_entry("testnops", NULL);
  99 }
 100
 101 MODULE_LICENSE("GPL");
 102 MODULE_AUTHOR("Mathieu Desnoyers");
 103 MODULE_DESCRIPTION("Marker Test");
 104