4 * Doesn't transfer any data, merely burns CPU cycles according to
9 #include "../optgroup.h"
11 // number of 32 bit integers to sort
12 size_t qsort_size = (256 * (1ULL << 10)); // 256KB
27 unsigned int cpucycle;
28 enum stress_mode cpumode;
29 unsigned int exit_io_done;
33 static struct fio_option options[] = {
38 .off1 = offsetof(struct cpu_options, cpuload),
39 .help = "Use this percentage of CPU",
40 .category = FIO_OPT_C_ENGINE,
41 .group = FIO_OPT_G_INVALID,
47 .help = "Stress mode",
48 .off1 = offsetof(struct cpu_options, cpumode),
53 .help = "NOOP instructions",
56 .oval = FIO_CPU_QSORT,
57 .help = "QSORT computation",
60 .category = FIO_OPT_C_ENGINE,
61 .group = FIO_OPT_G_INVALID,
67 .off1 = offsetof(struct cpu_options, cpucycle),
68 .help = "Length of the CPU burn cycles (usecs)",
72 .category = FIO_OPT_C_ENGINE,
73 .group = FIO_OPT_G_INVALID,
76 .name = "exit_on_io_done",
77 .lname = "Exit when IO threads are done",
79 .off1 = offsetof(struct cpu_options, exit_io_done),
80 .help = "Exit when IO threads finish",
82 .category = FIO_OPT_C_ENGINE,
83 .group = FIO_OPT_G_INVALID,
92 * Multiply-with-carry random numbers
93 * fast pseudo random number generator, see
94 * http://www.cse.yorku.ca/~oz/marsaglia-rng.html
96 uint32_t mwc32(struct mwc *mwc)
98 mwc->z = 36969 * (mwc->z & 65535) + (mwc->z >> 16);
99 mwc->w = 18000 * (mwc->w & 65535) + (mwc->w >> 16);
100 return (mwc->z << 16) + mwc->w;
104 * stress_qsort_cmp_1()
105 * qsort comparison - sort on int32 values
107 static int stress_qsort_cmp_1(const void *p1, const void *p2)
109 const int32_t *i1 = (const int32_t *)p1;
110 const int32_t *i2 = (const int32_t *)p2;
121 * stress_qsort_cmp_2()
122 * qsort comparison - reverse sort on int32 values
124 static int stress_qsort_cmp_2(const void *p1, const void *p2)
126 return stress_qsort_cmp_1(p2, p1);
130 * stress_qsort_cmp_3()
131 * qsort comparison - sort on int8 values
133 static int stress_qsort_cmp_3(const void *p1, const void *p2)
135 const int8_t *i1 = (const int8_t *)p1;
136 const int8_t *i2 = (const int8_t *)p2;
138 /* Force re-ordering on 8 bit value */
142 static int do_qsort(struct thread_data *td)
144 struct thread_options *o = &td->o;
145 struct cpu_options *co = td->eo;
146 struct timespec start, now;
148 fio_get_mono_time(&start);
150 /* Sort "random" data */
151 qsort(co->qsort_data, qsort_size, sizeof(*(co->qsort_data)), stress_qsort_cmp_1);
154 qsort(co->qsort_data, qsort_size, sizeof(*(co->qsort_data)), stress_qsort_cmp_2);
156 /* And re-order by byte compare */
157 qsort((uint8_t *)co->qsort_data, qsort_size * 4, sizeof(uint8_t), stress_qsort_cmp_3);
159 /* Reverse sort this again */
160 qsort(co->qsort_data, qsort_size, sizeof(*(co->qsort_data)), stress_qsort_cmp_2);
161 fio_get_mono_time(&now);
163 /* Adjusting cpucycle automatically to be as close as possible to the
164 * expected cpuload The time to execute do_qsort() may change over time
165 * as per : - the job concurrency - the cpu clock adjusted by the power
166 * management After every do_qsort() call, the next thinktime is
167 * adjusted regarding the last run performance
169 co->cpucycle = utime_since(&start, &now);
170 o->thinktime = ((unsigned long long) co->cpucycle *
171 (100 - co->cpuload)) / co->cpuload;
176 static enum fio_q_status fio_cpuio_queue(struct thread_data *td,
177 struct io_u fio_unused *io_u)
179 struct cpu_options *co = td->eo;
181 if (co->exit_io_done && !fio_running_or_pending_io_threads()) {
186 switch (co->cpumode) {
188 usec_spin(co->cpucycle);
195 return FIO_Q_COMPLETED;
198 static int noop_init(struct thread_data *td)
200 struct cpu_options *co = td->eo;
202 log_info("%s (noop): ioengine=%s, cpuload=%u, cpucycle=%u\n",
203 td->o.name, td->io_ops->name, co->cpuload, co->cpucycle);
207 static int qsort_cleanup(struct thread_data *td)
209 struct cpu_options *co = td->eo;
211 if (co->qsort_data) {
212 free(co->qsort_data);
213 co->qsort_data = NULL;
219 static int qsort_init(struct thread_data *td)
221 /* Setting up a default entropy */
222 struct mwc mwc = { 521288629UL, 362436069UL };
223 struct cpu_options *co = td->eo;
227 co->qsort_data = calloc(qsort_size, sizeof(*co->qsort_data));
228 if (co->qsort_data == NULL) {
229 td_verror(td, ENOMEM, "qsort_init");
233 /* This is expensive, init the memory once */
234 for (ptr = co->qsort_data, i = 0; i < qsort_size; i++)
235 *ptr++ = mwc32(&mwc);
237 log_info("%s (qsort): ioengine=%s, cpuload=%u, cpucycle=%u\n",
238 td->o.name, td->io_ops->name, co->cpuload, co->cpucycle);
243 static int fio_cpuio_init(struct thread_data *td)
245 struct thread_options *o = &td->o;
246 struct cpu_options *co = td->eo;
247 int td_previous_state;
251 td_vmsg(td, EINVAL, "cpu thread needs rate (cpuload=)","cpuio");
255 if (co->cpuload > 100)
258 /* Saving the current thread state */
259 td_previous_state = td->runstate;
261 /* Reporting that we are preparing the engine
262 * This is useful as the qsort() calibration takes time
263 * This prevents the job from starting before init is completed
265 td_set_runstate(td, TD_SETTING_UP);
268 * set thinktime_sleep and thinktime_spin appropriately
270 o->thinktime_blocks = 1;
271 o->thinktime_blocks_type = THINKTIME_BLOCKS_TYPE_COMPLETE;
272 o->thinktime_spin = 0;
273 o->thinktime = ((unsigned long long) co->cpucycle *
274 (100 - co->cpuload)) / co->cpuload;
276 o->nr_files = o->open_files = 1;
278 switch (co->cpumode) {
286 if (asprintf(&msg, "bad cpu engine mode: %d", co->cpumode) < 0)
288 td_vmsg(td, EINVAL, msg ? : "(?)", __func__);
293 /* Let's restore the previous state. */
294 td_set_runstate(td, td_previous_state);
298 static void fio_cpuio_cleanup(struct thread_data *td)
300 struct cpu_options *co = td->eo;
302 switch (co->cpumode) {
311 static int fio_cpuio_open(struct thread_data fio_unused *td,
312 struct fio_file fio_unused *f)
317 static struct ioengine_ops ioengine = {
319 .version = FIO_IOOPS_VERSION,
320 .queue = fio_cpuio_queue,
321 .init = fio_cpuio_init,
322 .cleanup = fio_cpuio_cleanup,
323 .open_file = fio_cpuio_open,
324 .flags = FIO_SYNCIO | FIO_DISKLESSIO | FIO_NOIO,
326 .option_struct_size = sizeof(struct cpu_options),
329 static void fio_init fio_cpuio_register(void)
331 register_ioengine(&ioengine);
334 static void fio_exit fio_cpuio_unregister(void)
336 unregister_ioengine(&ioengine);