| 1 | /* test-time-probe.c |
| 2 | * |
| 3 | * Test time spent in a LTTng instrumentation probe. |
| 4 | */ |
| 5 | |
| 6 | |
| 7 | #define CONFIG_LTT_FACILITY_TESTS |
| 8 | #include "ltt-facility-tests.h" |
| 9 | |
| 10 | #include <linux/init.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/ltt-core.h> |
| 13 | |
| 14 | |
| 15 | /* Event logged : 4 bytes + 20 bytes header = 24 bytes. Let's use 1MB of |
| 16 | * buffers. 1MB / 24bytes = 43690. So, if we write 20000 event, we should not |
| 17 | * lose events. Check event lost count after tests. */ |
| 18 | |
| 19 | #define NR_LOOPS 20000 |
| 20 | |
| 21 | static int ltt_test_init(void) |
| 22 | { |
| 23 | unsigned int i; |
| 24 | cycles_t time1, time2, time; |
| 25 | cycles_t max_time = 0, min_time = 18446744073709551615ULL; /* (2^64)-1 */ |
| 26 | cycles_t tot_time = 0; |
| 27 | unsigned long flags; |
| 28 | printk(KERN_ALERT "test init\n"); |
| 29 | |
| 30 | local_irq_save(flags); |
| 31 | for(i=0; i<NR_LOOPS; i++) { |
| 32 | time1 = get_cycles(); |
| 33 | trace_tests_write_4bytes(5000); |
| 34 | time2 = get_cycles(); |
| 35 | time = time2 - time1; |
| 36 | max_time = max(max_time, time); |
| 37 | min_time = min(min_time, time); |
| 38 | tot_time += time; |
| 39 | } |
| 40 | local_irq_restore(flags); |
| 41 | |
| 42 | printk(KERN_ALERT "test results : time per probe\n"); |
| 43 | printk(KERN_ALERT "number of loops : %d\n", NR_LOOPS); |
| 44 | printk(KERN_ALERT "total time : %llu\n", tot_time); |
| 45 | printk(KERN_ALERT "min : %llu\n", min_time); |
| 46 | printk(KERN_ALERT "max : %llu\n", max_time); |
| 47 | |
| 48 | printk(KERN_ALERT "test end\n"); |
| 49 | |
| 50 | return -EAGAIN; /* Fail will directly unload the module */ |
| 51 | } |
| 52 | |
| 53 | static void ltt_test_exit(void) |
| 54 | { |
| 55 | printk(KERN_ALERT "test exit\n"); |
| 56 | } |
| 57 | |
| 58 | module_init(ltt_test_init) |
| 59 | module_exit(ltt_test_exit) |
| 60 | |
| 61 | MODULE_LICENSE("GPL"); |
| 62 | MODULE_AUTHOR("Mathieu Desnoyers"); |
| 63 | MODULE_DESCRIPTION("Linux Trace Toolkit Test"); |
| 64 | |