| 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 <asm/atomic.h> |
| 10 | #include <asm/ptrace.h> |
| 11 | |
| 12 | #define NR_TESTS 10000000 |
| 13 | |
| 14 | int var, var2; |
| 15 | atomic64_t atomicval; |
| 16 | |
| 17 | struct proc_dir_entry *pentry = NULL; |
| 18 | |
| 19 | |
| 20 | static inline long test_nop_atomic64_add_return(long i, atomic64_t *v) |
| 21 | { |
| 22 | long __i = i; |
| 23 | asm volatile(".byte 0x90;" |
| 24 | "xaddq %0, %1;" |
| 25 | : "+r" (i), "+m" (v->counter) |
| 26 | : : "memory"); |
| 27 | return i + __i; |
| 28 | } |
| 29 | |
| 30 | static inline long test_prefix_atomic64_add_return(long i, atomic64_t *v) |
| 31 | { |
| 32 | long __i = i; |
| 33 | asm volatile(".byte 0x3E;" |
| 34 | "xaddq %0, %1;" |
| 35 | : "+r" (i), "+m" (v->counter) |
| 36 | : : "memory"); |
| 37 | return i + __i; |
| 38 | } |
| 39 | |
| 40 | static inline long test_lock_atomic64_add_return(long i, atomic64_t *v) |
| 41 | { |
| 42 | long __i = i; |
| 43 | asm volatile(".byte 0xf0;" |
| 44 | "xaddq %0, %1;" |
| 45 | : "+r" (i), "+m" (v->counter) |
| 46 | : : "memory"); |
| 47 | return i + __i; |
| 48 | } |
| 49 | |
| 50 | |
| 51 | |
| 52 | void empty(void) |
| 53 | { |
| 54 | asm volatile (""); |
| 55 | var += 50; |
| 56 | var /= 10; |
| 57 | var *= var2; |
| 58 | } |
| 59 | |
| 60 | void testnop(void) |
| 61 | { |
| 62 | test_nop_atomic64_add_return(5, &atomicval); |
| 63 | var += 50; |
| 64 | var /= 10; |
| 65 | var *= var2; |
| 66 | } |
| 67 | |
| 68 | void testprefix(void) |
| 69 | { |
| 70 | test_prefix_atomic64_add_return(5, &atomicval); |
| 71 | var += 50; |
| 72 | var /= 10; |
| 73 | var *= var2; |
| 74 | } |
| 75 | |
| 76 | void testlock(void) |
| 77 | { |
| 78 | test_lock_atomic64_add_return(5, &atomicval); |
| 79 | var += 50; |
| 80 | var /= 10; |
| 81 | var *= var2; |
| 82 | } |
| 83 | |
| 84 | |
| 85 | |
| 86 | void perform_test(const char *name, void (*callback)(void)) |
| 87 | { |
| 88 | unsigned int i; |
| 89 | cycles_t cycles1, cycles2; |
| 90 | unsigned long flags; |
| 91 | |
| 92 | local_irq_save(flags); |
| 93 | rdtsc_barrier(); |
| 94 | cycles1 = get_cycles(); |
| 95 | rdtsc_barrier(); |
| 96 | for(i=0; i<NR_TESTS; i++) { |
| 97 | callback(); |
| 98 | } |
| 99 | rdtsc_barrier(); |
| 100 | cycles2 = get_cycles(); |
| 101 | rdtsc_barrier(); |
| 102 | local_irq_restore(flags); |
| 103 | printk("test %s cycles : %llu\n", name, cycles2-cycles1); |
| 104 | } |
| 105 | |
| 106 | static int my_open(struct inode *inode, struct file *file) |
| 107 | { |
| 108 | printk("NR_TESTS %d\n", NR_TESTS); |
| 109 | |
| 110 | perform_test("empty", empty); |
| 111 | printk("value : %ld\n", atomic64_read(&atomicval)); |
| 112 | perform_test("test 1-byte nop xadd", testnop); |
| 113 | printk("value : %ld\n", atomic64_read(&atomicval)); |
| 114 | perform_test("test DS override prefix xadd", testprefix); |
| 115 | printk("value : %ld\n", atomic64_read(&atomicval)); |
| 116 | perform_test("test LOCK xadd", testlock); |
| 117 | printk("value : %ld\n", atomic64_read(&atomicval)); |
| 118 | |
| 119 | return -EPERM; |
| 120 | } |
| 121 | |
| 122 | |
| 123 | static struct file_operations my_operations = { |
| 124 | .open = my_open, |
| 125 | }; |
| 126 | |
| 127 | int init_module(void) |
| 128 | { |
| 129 | pentry = create_proc_entry("testprefix", 0444, NULL); |
| 130 | if (pentry) |
| 131 | pentry->proc_fops = &my_operations; |
| 132 | |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | void cleanup_module(void) |
| 137 | { |
| 138 | remove_proc_entry("testprefix", NULL); |
| 139 | } |
| 140 | |
| 141 | MODULE_LICENSE("GPL"); |
| 142 | MODULE_AUTHOR("Mathieu Desnoyers"); |
| 143 | MODULE_DESCRIPTION("prefix test"); |