blob: c798f1884e8dff8df9b079d87d61c8c4259ae10c [file] [log] [blame]
/*
* CPU engine
*
* Doesn't transfer any data, merely burns CPU cycles according to
* the settings.
*
*/
#include "../fio.h"
struct cpu_options {
struct thread_data *td;
unsigned int cpuload;
unsigned int cpucycle;
};
static struct fio_option options[] = {
{
.name = "cpuload",
.lname = "CPU load",
.type = FIO_OPT_INT,
.off1 = offsetof(struct cpu_options, cpuload),
.help = "Use this percentage of CPU",
.category = FIO_OPT_C_GENERAL,
.group = FIO_OPT_G_INVALID,
},
{
.name = "cpuchunks",
.lname = "CPU chunk",
.type = FIO_OPT_INT,
.off1 = offsetof(struct cpu_options, cpucycle),
.help = "Length of the CPU burn cycles (usecs)",
.def = "50000",
.parent = "cpuload",
.hide = 1,
.category = FIO_OPT_C_GENERAL,
.group = FIO_OPT_G_INVALID,
},
{
.name = NULL,
},
};
static int fio_cpuio_queue(struct thread_data *td, struct io_u fio_unused *io_u)
{
struct cpu_options *co = td->eo;
usec_spin(co->cpucycle);
return FIO_Q_COMPLETED;
}
static int fio_cpuio_init(struct thread_data *td)
{
struct thread_options *o = &td->o;
struct cpu_options *co = td->eo;
if (!co->cpuload) {
td_vmsg(td, EINVAL, "cpu thread needs rate (cpuload=)","cpuio");
return 1;
}
if (co->cpuload > 100)
co->cpuload = 100;
/*
* set thinktime_sleep and thinktime_spin appropriately
*/
o->thinktime_blocks = 1;
o->thinktime_spin = 0;
o->thinktime = (co->cpucycle * (100 - co->cpuload)) / co->cpuload;
o->nr_files = o->open_files = 1;
log_info("%s: ioengine=cpu, cpuload=%u, cpucycle=%u\n", td->o.name,
co->cpuload, co->cpucycle);
return 0;
}
static int fio_cpuio_open(struct thread_data fio_unused *td,
struct fio_file fio_unused *f)
{
return 0;
}
static struct ioengine_ops ioengine = {
.name = "cpuio",
.version = FIO_IOOPS_VERSION,
.queue = fio_cpuio_queue,
.init = fio_cpuio_init,
.open_file = fio_cpuio_open,
.flags = FIO_SYNCIO | FIO_DISKLESSIO | FIO_NOIO,
.options = options,
.option_struct_size = sizeof(struct cpu_options),
};
static void fio_init fio_cpuio_register(void)
{
register_ioengine(&ioengine);
}
static void fio_exit fio_cpuio_unregister(void)
{
unregister_ioengine(&ioengine);
}