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1 | /* test-time-probe.c |
2 | * |
3 | * Test time spent in a LTTng instrumentation probe. |
4 | */ |
5 | |
6 | |
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7 | #define CONFIG_LTT_FACILITY_TESTS |
8 | #include "ltt-facility-tests.h" |
9 | |
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10 | #include <linux/init.h> |
11 | #include <linux/module.h> |
12 | #include <linux/ltt-core.h> |
13 | |
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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 | |
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21 | static int ltt_test_init(void) |
22 | { |
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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; |
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28 | printk(KERN_ALERT "test init\n"); |
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29 | |
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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); |
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47 | |
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48 | printk(KERN_ALERT "test end\n"); |
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49 | |
50 | return -EAGAIN; /* Fail will directly unload the module */ |
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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 | |