1 /*
2 * Copyright (c) 2018 Google, Inc.
3 *
4 * SPDX-License-Identifier: GPL-2.0-or-later
5 *
6 * A test schedboost cgroup is created and a task is put inside it. The
7 * utilization of that task is monitored and verified while changing the boost
8 * of the test schedboost cgroup to different values.
9 */
10
11 #define _GNU_SOURCE
12 #include <errno.h>
13 #include <pthread.h>
14 #include <sched.h>
15 #include <semaphore.h>
16 #include <time.h>
17
18 #include "tst_test.h"
19 #include "tst_safe_file_ops.h"
20 #include "tst_safe_pthread.h"
21 #include "tst_safe_macros.h"
22
23 #include "trace_parse.h"
24 #include "util.h"
25
26 #define TRACE_EVENTS "sugov_util_update sched_switch"
27
28 static sem_t test_sem;
29 static sem_t result_sem;
30 static int test_cpu;
31 static int task_pid;
32 static unsigned int test_index = 0;
33 static int test_boost[] = { 0, 25, 50, 75, 100 };
34 #define NUM_TESTS (sizeof(test_boost)/sizeof(int))
35 static int test_utils[NUM_TESTS];
36 #define STUNE_TEST_PATH "/dev/stune/test"
37 #define STUNE_ROOT_TASKS "/dev/stune/tasks"
38
39 #define BUSY_USEC 1000
40 #define SLEEP_USEC 19000
41 /* Run each test for one second. */
42 #define TEST_LENGTH_USEC USEC_PER_SEC
43
do_work(void)44 static void do_work(void)
45 {
46 struct timespec ts;
47 unsigned long long now_usec, end_usec;
48
49 /* Calculate overall end time. */
50 if (clock_gettime(CLOCK_MONOTONIC, &ts)) {
51 printf("clock_gettime() reported an error\n");
52 return;
53 }
54 now_usec = ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / 1000;
55 end_usec = now_usec + TEST_LENGTH_USEC/2;
56
57 while (now_usec < end_usec) {
58 burn(BUSY_USEC, 0);
59 usleep(SLEEP_USEC);
60 if (clock_gettime(CLOCK_MONOTONIC, &ts)) {
61 printf("clock_gettime() reported an error\n");
62 return;
63 }
64 now_usec = ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / 1000;
65 }
66 }
67
test_fn(void * arg LTP_ATTRIBUTE_UNUSED)68 static void *test_fn(void *arg LTP_ATTRIBUTE_UNUSED)
69 {
70 unsigned int tests_done = 0;
71
72 affine(test_cpu);
73
74 task_pid = gettid();
75 SAFE_FILE_PRINTF(STUNE_TEST_PATH "/tasks", "%d", task_pid);
76 while(tests_done < NUM_TESTS) {
77 sem_wait(&test_sem);
78 // give time for utilization to track real task usage
79 do_work();
80 // start measuring
81 tracefs_write("tracing_on", "1");
82 do_work();
83 sem_post(&result_sem);
84 tests_done++;
85 }
86 SAFE_FILE_PRINTF(STUNE_ROOT_TASKS, "%d", task_pid);
87 return NULL;
88 }
89
parse_results(void)90 static int parse_results(void)
91 {
92 int i;
93 int max_util_seen = 0;
94
95 for (i = 0; i < num_trace_records; i++)
96 if (trace[i].event_type == TRACE_RECORD_SUGOV_UTIL_UPDATE) {
97 struct trace_sugov_util_update *t =
98 trace[i].event_data;
99 if (t->cpu == test_cpu && t->util > max_util_seen)
100 max_util_seen = t->util;
101 }
102
103 test_utils[test_index] = max_util_seen;
104 printf("Max util seen for boost %d: %d\n", test_boost[test_index],
105 max_util_seen);
106 return 0;
107 }
108
run_test(void)109 static void run_test(void)
110 {
111 SAFE_FILE_PRINTF(STUNE_TEST_PATH "/schedtune.boost",
112 "%d", test_boost[test_index]);
113 tracefs_write("trace", "\n");
114 sem_post(&test_sem);
115 sem_wait(&result_sem);
116 tracefs_write("tracing_on", "0");
117 LOAD_TRACE();
118 parse_results();
119 test_index++;
120 }
121
122 #define TEST_MARGIN 50
check_results(void)123 static void check_results(void)
124 {
125 unsigned int i;
126 for (i = 0; i < NUM_TESTS; i++) {
127 int target_util = test_boost[i] * 10;
128 if (test_utils[i] < target_util - TEST_MARGIN ||
129 test_utils[i] > target_util + TEST_MARGIN)
130 tst_res(TFAIL, "Test %i (boost %d) failed with "
131 "util %d (allowed %d - %d).\n",
132 i, test_boost[i], test_utils[i],
133 target_util - TEST_MARGIN,
134 target_util + TEST_MARGIN);
135 else
136 tst_res(TPASS, "Test %i (boost %d) passed with "
137 "util %d (allowed %d - %d).\n",
138 i, test_boost[i], test_utils[i],
139 target_util - TEST_MARGIN,
140 target_util + TEST_MARGIN);
141 }
142 }
143
run(void)144 static void run(void)
145 {
146 pthread_t test_thread;
147
148 sem_init(&test_sem, 0, 0);
149 sem_init(&result_sem, 0, 0);
150
151 if (access("/dev/stune", R_OK))
152 tst_brk(TCONF, "schedtune not detected");
153
154 test_cpu = tst_ncpus() - 1;
155 printf("Running %ld tests for %d sec\n", NUM_TESTS,
156 TEST_LENGTH_USEC / USEC_PER_SEC);
157 printf("CPU hog will be bound to CPU %d.\n", test_cpu);
158
159 /*
160 * If this fails due to ENOSPC the definition of BOOSTGROUPS_COUNT in
161 * kernel/sched/tune.c needs to be increased.
162 */
163 SAFE_MKDIR(STUNE_TEST_PATH, 0777);
164 if (access(STUNE_TEST_PATH "/schedtune.colocate", W_OK) != -1) {
165 SAFE_FILE_PRINTF(STUNE_TEST_PATH "/schedtune.colocate",
166 "0");
167 }
168 if (access(STUNE_TEST_PATH "/schedtune.prefer_idle", W_OK) != -1) {
169 SAFE_FILE_PRINTF(STUNE_TEST_PATH "/schedtune.prefer_idle",
170 "0");
171 }
172 if (access(STUNE_TEST_PATH "/schedtune.sched_boost_enabled", W_OK) !=
173 -1) {
174 SAFE_FILE_PRINTF(STUNE_TEST_PATH "/schedtune.sched_boost_enabled",
175 "1");
176 }
177 if (access(STUNE_TEST_PATH "/schedtune.sched_boost_no_override",
178 W_OK) != -1) {
179 SAFE_FILE_PRINTF(STUNE_TEST_PATH "/schedtune.sched_boost_no_override",
180 "0");
181 }
182
183 SAFE_PTHREAD_CREATE(&test_thread, NULL, test_fn, NULL);
184
185 tracefs_write("tracing_on", "0");
186 tracefs_write("buffer_size_kb", "16384");
187 tracefs_write("set_event", TRACE_EVENTS);
188
189 while (test_index < NUM_TESTS)
190 run_test();
191
192 SAFE_PTHREAD_JOIN(test_thread, NULL);
193 SAFE_RMDIR(STUNE_TEST_PATH);
194 check_results();
195 }
196
197 static struct tst_test test = {
198 .test_all = run,
199 .setup = trace_setup,
200 .cleanup = trace_cleanup,
201 };
202