| 1 | /* |
| 2 | * lttng-ust-getcpu-override-test.c |
| 3 | * Based on lttng-getcpu-override-example.c from LTTng-ust exemple |
| 4 | * |
| 5 | * Copyright (C) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 6 | * Copyright (C) 2015 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com> |
| 7 | * |
| 8 | * SPDX-License-Identifier: MIT |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | #include <common/compat/time.hpp> |
| 13 | |
| 14 | #include <lttng/lttng-export.h> |
| 15 | #include <lttng/ust-getcpu.h> |
| 16 | |
| 17 | #include <stdio.h> |
| 18 | #include <stdlib.h> |
| 19 | #include <string.h> |
| 20 | #include <unistd.h> |
| 21 | |
| 22 | static long nprocessors; |
| 23 | |
| 24 | static int plugin_getcpu(void) |
| 25 | { |
| 26 | /* Generate a sequence based on the number of configurated processor |
| 27 | * by using sequence[i] % nb_configured_processors. Where sequence |
| 28 | * is a static random sequence. |
| 29 | * The expected cpu_id sequence can be regenerated on the test script |
| 30 | * side and compared to the extracted cpu sequence for validation. |
| 31 | * This does no guarantee in absolute the validity of the getcpu |
| 32 | * plugin but provide a strong argument of it's validity. |
| 33 | */ |
| 34 | static int i = 0; |
| 35 | static int seq_seed[256] = { |
| 36 | 100, 57, 232, 236, 42, 193, 224, 184, 216, 150, 92, 91, 108, 118, 55, 243, |
| 37 | 65, 101, 209, 0, 147, 36, 29, 34, 49, 188, 174, 105, 253, 245, 227, 238, |
| 38 | 112, 20, 222, 201, 102, 175, 119, 19, 132, 41, 78, 90, 114, 64, 138, 14, |
| 39 | 48, 18, 162, 85, 204, 124, 133, 73, 172, 106, 241, 126, 28, 104, 111, 21, |
| 40 | 127, 219, 9, 244, 237, 189, 59, 214, 52, 141, 107, 26, 25, 199, 3, 157, |
| 41 | 117, 234, 33, 44, 46, 84, 69, 155, 122, 250, 231, 86, 239, 76, 190, 120, |
| 42 | 1, 94, 206, 8, 148, 159, 167, 215, 164, 31, 217, 61, 71, 125, 68, 109, |
| 43 | 195, 177, 95, 82, 142, 182, 129, 87, 37, 140, 134, 186, 173, 39, 116, 143, |
| 44 | 254, 229, 131, 67, 121, 192, 240, 15, 221, 30, 242, 185, 80, 170, 135, 51, |
| 45 | 187, 194, 246, 12, 225, 181, 137, 211, 228, 88, 218, 27, 233, 161, 77, 252, |
| 46 | 123, 93, 220, 248, 205, 223, 144, 128, 196, 70, 247, 210, 178, 203, 154, 24, |
| 47 | 169, 149, 163, 35, 7, 151, 103, 197, 139, 165, 158, 207, 72, 113, 145, 45, |
| 48 | 183, 11, 198, 43, 81, 230, 97, 96, 2, 66, 213, 146, 179, 22, 58, 54, |
| 49 | 38, 160, 200, 235, 226, 156, 56, 208, 249, 32, 176, 168, 110, 191, 79, 152, |
| 50 | 115, 10, 74, 60, 251, 17, 83, 180, 171, 202, 40, 166, 255, 53, 212, 98, |
| 51 | 5, 50, 99, 4, 89, 13, 63, 6, 136, 153, 23, 16, 47, 130, 75, 62 |
| 52 | }; |
| 53 | int ret; |
| 54 | |
| 55 | ret = seq_seed[i] % nprocessors; |
| 56 | i++; |
| 57 | i = i % 256; |
| 58 | return ret; |
| 59 | } |
| 60 | |
| 61 | LTTNG_EXPORT void lttng_ust_getcpu_plugin_init(void); |
| 62 | void lttng_ust_getcpu_plugin_init(void) |
| 63 | { |
| 64 | int ret; |
| 65 | |
| 66 | nprocessors = sysconf(_SC_NPROCESSORS_CONF); |
| 67 | if (nprocessors < 0) { |
| 68 | perror("Failed to get _SC_NPROCESSORS_CONF"); |
| 69 | goto error; |
| 70 | } |
| 71 | |
| 72 | ret = lttng_ust_getcpu_override(plugin_getcpu); |
| 73 | if (ret) { |
| 74 | fprintf(stderr, "Error enabling getcpu override: %s\n", strerror(-ret)); |
| 75 | goto error; |
| 76 | } |
| 77 | return; |
| 78 | |
| 79 | error: |
| 80 | exit(EXIT_FAILURE); |
| 81 | } |