[fio.git] / engines / cpu.c

/*
 * 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);
}
Commit	Line	Data
	1	/*
	2	* CPU engine
	3	*
	4	* Doesn't transfer any data, merely burns CPU cycles according to
	5	* the settings.
	6	*
	7	*/
	8	#include "../fio.h"
	9
	10	struct cpu_options {
	11	struct thread_data *td;
	12	unsigned int cpuload;
	13	unsigned int cpucycle;
	14	};
	15
	16	static struct fio_option options[] = {
	17	{
	18	.name = "cpuload",
	19	.lname = "CPU load",
	20	.type = FIO_OPT_INT,
	21	.off1 = offsetof(struct cpu_options, cpuload),
	22	.help = "Use this percentage of CPU",
	23	.category = FIO_OPT_C_GENERAL,
	24	.group = FIO_OPT_G_INVALID,
	25	},
	26	{
	27	.name = "cpuchunks",
	28	.lname = "CPU chunk",
	29	.type = FIO_OPT_INT,
	30	.off1 = offsetof(struct cpu_options, cpucycle),
	31	.help = "Length of the CPU burn cycles (usecs)",
	32	.def = "50000",
	33	.parent = "cpuload",
	34	.hide = 1,
	35	.category = FIO_OPT_C_GENERAL,
	36	.group = FIO_OPT_G_INVALID,
	37	},
	38	{
	39	.name = NULL,
	40	},
	41	};
	42
	43
	44	static int fio_cpuio_queue(struct thread_data td, struct io_u fio_unused io_u)
	45	{
	46	struct cpu_options *co = td->eo;
	47
	48	usec_spin(co->cpucycle);
	49	return FIO_Q_COMPLETED;
	50	}
	51
	52	static int fio_cpuio_init(struct thread_data *td)
	53	{
	54	struct thread_options *o = &td->o;
	55	struct cpu_options *co = td->eo;
	56
	57	if (!co->cpuload) {
	58	td_vmsg(td, EINVAL, "cpu thread needs rate (cpuload=)","cpuio");
	59	return 1;
	60	}
	61
	62	if (co->cpuload > 100)
	63	co->cpuload = 100;
	64
	65	/*
	66	* set thinktime_sleep and thinktime_spin appropriately
	67	*/
	68	o->thinktime_blocks = 1;
	69	o->thinktime_spin = 0;
	70	o->thinktime = (co->cpucycle * (100 - co->cpuload)) / co->cpuload;
	71
	72	o->nr_files = o->open_files = 1;
	73
	74	log_info("%s: ioengine=cpu, cpuload=%u, cpucycle=%u\n", td->o.name,
	75	co->cpuload, co->cpucycle);
	76
	77	return 0;
	78	}
	79
	80	static int fio_cpuio_open(struct thread_data fio_unused *td,
	81	struct fio_file fio_unused *f)
	82	{
	83	return 0;
	84	}
	85
	86	static struct ioengine_ops ioengine = {
	87	.name = "cpuio",
	88	.version = FIO_IOOPS_VERSION,
	89	.queue = fio_cpuio_queue,
	90	.init = fio_cpuio_init,
	91	.open_file = fio_cpuio_open,
	92	.flags = FIO_SYNCIO \| FIO_DISKLESSIO \| FIO_NOIO,
	93	.options = options,
	94	.option_struct_size = sizeof(struct cpu_options),
	95	};
	96
	97	static void fio_init fio_cpuio_register(void)
	98	{
	99	register_ioengine(&ioengine);
	100	}
	101
	102	static void fio_exit fio_cpuio_unregister(void)
	103	{
	104	unregister_ioengine(&ioengine);
	105	}