[fio.git] / steadystate.c

#include <stdlib.h>

#include "fio.h"
#include "steadystate.h"

bool steadystate_enabled = false;
unsigned int ss_check_interval = 1000;

void steadystate_free(struct thread_data *td)
{
	free(td->ss.iops_data);
	free(td->ss.bw_data);
	td->ss.iops_data = NULL;
	td->ss.bw_data = NULL;
}

static void steadystate_alloc(struct thread_data *td)
{
	int intervals = td->ss.dur / (ss_check_interval / 1000L);

	td->ss.bw_data = calloc(intervals, sizeof(uint64_t));
	td->ss.iops_data = calloc(intervals, sizeof(uint64_t));

	td->ss.state |= FIO_SS_DATA;
}

void steadystate_setup(void)
{
	struct thread_data *prev_td;
	int prev_groupid;

	if (!steadystate_enabled)
		return;

	/*
	 * if group reporting is enabled, identify the last td
	 * for each group and use it for storing steady state
	 * data
	 */
	prev_groupid = -1;
	prev_td = NULL;
	for_each_td(td) {
		if (!td->ss.dur)
			continue;

		if (!td->o.group_reporting) {
			steadystate_alloc(td);
			continue;
		}

		if (prev_groupid != td->groupid) {
			if (prev_td)
				steadystate_alloc(prev_td);
			prev_groupid = td->groupid;
		}
		prev_td = td;
	} end_for_each();

	if (prev_td && prev_td->o.group_reporting)
		steadystate_alloc(prev_td);
}

static bool steadystate_slope(uint64_t iops, uint64_t bw,
			      struct thread_data *td)
{
	int i, j;
	double result;
	struct steadystate_data *ss = &td->ss;
	uint64_t new_val;
	int intervals = ss->dur / (ss_check_interval / 1000L);

	ss->bw_data[ss->tail] = bw;
	ss->iops_data[ss->tail] = iops;

	if (ss->state & FIO_SS_IOPS)
		new_val = iops;
	else
		new_val = bw;

	if (ss->state & FIO_SS_BUFFER_FULL || ss->tail - ss->head == intervals - 1) {
		if (!(ss->state & FIO_SS_BUFFER_FULL)) {
			/* first time through */
			for (i = 0, ss->sum_y = 0; i < intervals; i++) {
				if (ss->state & FIO_SS_IOPS)
					ss->sum_y += ss->iops_data[i];
				else
					ss->sum_y += ss->bw_data[i];
				j = (ss->head + i) % intervals;
				if (ss->state & FIO_SS_IOPS)
					ss->sum_xy += i * ss->iops_data[j];
				else
					ss->sum_xy += i * ss->bw_data[j];
			}
			ss->state |= FIO_SS_BUFFER_FULL;
		} else {		/* easy to update the sums */
			ss->sum_y -= ss->oldest_y;
			ss->sum_y += new_val;
			ss->sum_xy = ss->sum_xy - ss->sum_y + intervals * new_val;
		}

		if (ss->state & FIO_SS_IOPS)
			ss->oldest_y = ss->iops_data[ss->head];
		else
			ss->oldest_y = ss->bw_data[ss->head];

		/*
		 * calculate slope as (sum_xy - sum_x * sum_y / n) / (sum_(x^2)
		 * - (sum_x)^2 / n) This code assumes that all x values are
		 * equally spaced when they are often off by a few milliseconds.
		 * This assumption greatly simplifies the calculations.
		 */
		ss->slope = (ss->sum_xy - (double) ss->sum_x * ss->sum_y / intervals) /
				(ss->sum_x_sq - (double) ss->sum_x * ss->sum_x / intervals);
		if (ss->state & FIO_SS_PCT)
			ss->criterion = 100.0 * ss->slope / (ss->sum_y / intervals);
		else
			ss->criterion = ss->slope;

		dprint(FD_STEADYSTATE, "sum_y: %llu, sum_xy: %llu, slope: %f, "
					"criterion: %f, limit: %f\n",
					(unsigned long long) ss->sum_y,
					(unsigned long long) ss->sum_xy,
					ss->slope, ss->criterion, ss->limit);

		result = ss->criterion * (ss->criterion < 0.0 ? -1.0 : 1.0);
		if (result < ss->limit)
			return true;
	}

	ss->tail = (ss->tail + 1) % intervals;
	if (ss->tail <= ss->head)
		ss->head = (ss->head + 1) % intervals;

	return false;
}

static bool steadystate_deviation(uint64_t iops, uint64_t bw,
				  struct thread_data *td)
{
	int i;
	double diff;
	double mean;

	struct steadystate_data *ss = &td->ss;
	int intervals = ss->dur / (ss_check_interval / 1000L);

	ss->bw_data[ss->tail] = bw;
	ss->iops_data[ss->tail] = iops;

	if (ss->state & FIO_SS_BUFFER_FULL || ss->tail - ss->head == intervals  - 1) {
		if (!(ss->state & FIO_SS_BUFFER_FULL)) {
			/* first time through */
			for (i = 0, ss->sum_y = 0; i < intervals; i++) {
				if (ss->state & FIO_SS_IOPS)
					ss->sum_y += ss->iops_data[i];
				else
					ss->sum_y += ss->bw_data[i];
			}
			ss->state |= FIO_SS_BUFFER_FULL;
		} else {		/* easy to update the sum */
			ss->sum_y -= ss->oldest_y;
			if (ss->state & FIO_SS_IOPS)
				ss->sum_y += ss->iops_data[ss->tail];
			else
				ss->sum_y += ss->bw_data[ss->tail];
		}

		if (ss->state & FIO_SS_IOPS)
			ss->oldest_y = ss->iops_data[ss->head];
		else
			ss->oldest_y = ss->bw_data[ss->head];

		mean = (double) ss->sum_y / intervals;
		ss->deviation = 0.0;

		for (i = 0; i < intervals; i++) {
			if (ss->state & FIO_SS_IOPS)
				diff = ss->iops_data[i] - mean;
			else
				diff = ss->bw_data[i] - mean;
			ss->deviation = max(ss->deviation, diff * (diff < 0.0 ? -1.0 : 1.0));
		}

		if (ss->state & FIO_SS_PCT)
			ss->criterion = 100.0 * ss->deviation / mean;
		else
			ss->criterion = ss->deviation;

		dprint(FD_STEADYSTATE, "intervals: %d, sum_y: %llu, mean: %f, max diff: %f, "
					"objective: %f, limit: %f\n",
					intervals,
					(unsigned long long) ss->sum_y, mean,
					ss->deviation, ss->criterion, ss->limit);

		if (ss->criterion < ss->limit)
			return true;
	}

	ss->tail = (ss->tail + 1) % intervals;
	if (ss->tail == ss->head)
		ss->head = (ss->head + 1) % intervals;

	return false;
}

int steadystate_check(void)
{
	int  ddir, prev_groupid, group_ramp_time_over = 0;
	unsigned long rate_time;
	struct timespec now;
	uint64_t group_bw = 0, group_iops = 0;
	uint64_t td_iops, td_bytes;
	bool ret;

	prev_groupid = -1;
	for_each_td(td) {
		const bool needs_lock = td_async_processing(td);
		struct steadystate_data *ss = &td->ss;

		if (!ss->dur || td->runstate <= TD_SETTING_UP ||
		    td->runstate >= TD_EXITED || !ss->state ||
		    ss->state & FIO_SS_ATTAINED)
			continue;

		td_iops = 0;
		td_bytes = 0;
		if (!td->o.group_reporting ||
		    (td->o.group_reporting && td->groupid != prev_groupid)) {
			group_bw = 0;
			group_iops = 0;
			group_ramp_time_over = 0;
		}
		prev_groupid = td->groupid;

		fio_gettime(&now, NULL);
		if (ss->ramp_time && !(ss->state & FIO_SS_RAMP_OVER)) {
			/*
			 * Begin recording data one check interval after ss->ramp_time
			 * has elapsed
			 */
			if (utime_since(&td->epoch, &now) >= (ss->ramp_time + ss_check_interval * 1000L))
				ss->state |= FIO_SS_RAMP_OVER;
		}

		if (needs_lock)
			__td_io_u_lock(td);

		for (ddir = 0; ddir < DDIR_RWDIR_CNT; ddir++) {
			td_iops += td->io_blocks[ddir];
			td_bytes += td->io_bytes[ddir];
		}

		if (needs_lock)
			__td_io_u_unlock(td);

		rate_time = mtime_since(&ss->prev_time, &now);
		memcpy(&ss->prev_time, &now, sizeof(now));

		if (ss->state & FIO_SS_RAMP_OVER) {
			group_bw += rate_time * (td_bytes - ss->prev_bytes) /
				(ss_check_interval * ss_check_interval / 1000L);
			group_iops += rate_time * (td_iops - ss->prev_iops) /
				(ss_check_interval * ss_check_interval / 1000L);
			++group_ramp_time_over;
		}
		ss->prev_iops = td_iops;
		ss->prev_bytes = td_bytes;

		if (td->o.group_reporting && !(ss->state & FIO_SS_DATA))
			continue;

		/*
		 * Don't begin checking criterion until ss->ramp_time is over
		 * for at least one thread in group
		 */
		if (!group_ramp_time_over)
			continue;

		dprint(FD_STEADYSTATE, "steadystate_check() thread: %d, "
					"groupid: %u, rate_msec: %ld, "
					"iops: %llu, bw: %llu, head: %d, tail: %d\n",
					__td_index, td->groupid, rate_time,
					(unsigned long long) group_iops,
					(unsigned long long) group_bw,
					ss->head, ss->tail);

		if (ss->state & FIO_SS_SLOPE)
			ret = steadystate_slope(group_iops, group_bw, td);
		else
			ret = steadystate_deviation(group_iops, group_bw, td);

		if (ret) {
			if (td->o.group_reporting) {
				for_each_td(td2) {
					if (td2->groupid == td->groupid) {
						td2->ss.state |= FIO_SS_ATTAINED;
						fio_mark_td_terminate(td2);
					}
				} end_for_each();
			} else {
				ss->state |= FIO_SS_ATTAINED;
				fio_mark_td_terminate(td);
			}
		}
	} end_for_each();
	return 0;
}

int td_steadystate_init(struct thread_data *td)
{
	struct steadystate_data *ss = &td->ss;
	struct thread_options *o = &td->o;
	int intervals;

	memset(ss, 0, sizeof(*ss));

	if (o->ss_dur) {
		steadystate_enabled = true;
		o->ss_dur /= 1000000L;

		/* put all steady state info in one place */
		ss->dur = o->ss_dur;
		ss->limit = o->ss_limit.u.f;
		ss->ramp_time = o->ss_ramp_time;
		ss_check_interval = o->ss_check_interval / 1000L;

		ss->state = o->ss_state;
		if (!td->ss.ramp_time)
			ss->state |= FIO_SS_RAMP_OVER;

		intervals = ss->dur / (ss_check_interval / 1000L);
		ss->sum_x = intervals * (intervals - 1) / 2;
		ss->sum_x_sq = (intervals - 1) * (intervals) * (2*intervals - 1) / 6;
	}

	/* make sure that ss options are consistent within reporting group */
	for_each_td(td2) {
		if (td2->groupid == td->groupid) {
			struct steadystate_data *ss2 = &td2->ss;

			if (ss2->dur != ss->dur ||
			    ss2->limit != ss->limit ||
			    ss2->ramp_time != ss->ramp_time ||
			    ss2->state != ss->state ||
			    ss2->sum_x != ss->sum_x ||
			    ss2->sum_x_sq != ss->sum_x_sq) {
				td_verror(td, EINVAL, "job rejected: steadystate options must be consistent within reporting groups");
				return 1;
			}
		}
	} end_for_each();

	return 0;
}

uint64_t steadystate_bw_mean(struct thread_stat *ts)
{
	int i;
	uint64_t sum;
	int intervals = ts->ss_dur / (ss_check_interval / 1000L);
	
	if (!ts->ss_dur)
		return 0;

	for (i = 0, sum = 0; i < intervals; i++)
		sum += ts->ss_bw_data[i];

	return sum / intervals;
}

uint64_t steadystate_iops_mean(struct thread_stat *ts)
{
	int i;
	uint64_t sum;
	int intervals = ts->ss_dur / (ss_check_interval / 1000L);

	if (!ts->ss_dur)
		return 0;

	for (i = 0, sum = 0; i < intervals; i++)
		sum += ts->ss_iops_data[i];

	return sum / intervals;
}
Commit	Line	Data
	1	#include <stdlib.h>
	2
	3	#include "fio.h"
	4	#include "steadystate.h"
	5
	6	bool steadystate_enabled = false;
	7	unsigned int ss_check_interval = 1000;
	8
	9	void steadystate_free(struct thread_data *td)
	10	{
	11	free(td->ss.iops_data);
	12	free(td->ss.bw_data);
	13	td->ss.iops_data = NULL;
	14	td->ss.bw_data = NULL;
	15	}
	16
	17	static void steadystate_alloc(struct thread_data *td)
	18	{
	19	int intervals = td->ss.dur / (ss_check_interval / 1000L);
	20
	21	td->ss.bw_data = calloc(intervals, sizeof(uint64_t));
	22	td->ss.iops_data = calloc(intervals, sizeof(uint64_t));
	23
	24	td->ss.state \|= FIO_SS_DATA;
	25	}
	26
	27	void steadystate_setup(void)
	28	{
	29	struct thread_data *prev_td;
	30	int prev_groupid;
	31
	32	if (!steadystate_enabled)
	33	return;
	34
	35	/*
	36	* if group reporting is enabled, identify the last td
	37	* for each group and use it for storing steady state
	38	* data
	39	*/
	40	prev_groupid = -1;
	41	prev_td = NULL;
	42	for_each_td(td) {
	43	if (!td->ss.dur)
	44	continue;
	45
	46	if (!td->o.group_reporting) {
	47	steadystate_alloc(td);
	48	continue;
	49	}
	50
	51	if (prev_groupid != td->groupid) {
	52	if (prev_td)
	53	steadystate_alloc(prev_td);
	54	prev_groupid = td->groupid;
	55	}
	56	prev_td = td;
	57	} end_for_each();
	58
	59	if (prev_td && prev_td->o.group_reporting)
	60	steadystate_alloc(prev_td);
	61	}
	62
	63	static bool steadystate_slope(uint64_t iops, uint64_t bw,
	64	struct thread_data *td)
	65	{
	66	int i, j;
	67	double result;
	68	struct steadystate_data *ss = &td->ss;
	69	uint64_t new_val;
	70	int intervals = ss->dur / (ss_check_interval / 1000L);
	71
	72	ss->bw_data[ss->tail] = bw;
	73	ss->iops_data[ss->tail] = iops;
	74
	75	if (ss->state & FIO_SS_IOPS)
	76	new_val = iops;
	77	else
	78	new_val = bw;
	79
	80	if (ss->state & FIO_SS_BUFFER_FULL \|\| ss->tail - ss->head == intervals - 1) {
	81	if (!(ss->state & FIO_SS_BUFFER_FULL)) {
	82	/* first time through */
	83	for (i = 0, ss->sum_y = 0; i < intervals; i++) {
	84	if (ss->state & FIO_SS_IOPS)
	85	ss->sum_y += ss->iops_data[i];
	86	else
	87	ss->sum_y += ss->bw_data[i];
	88	j = (ss->head + i) % intervals;
	89	if (ss->state & FIO_SS_IOPS)
	90	ss->sum_xy += i * ss->iops_data[j];
	91	else
	92	ss->sum_xy += i * ss->bw_data[j];
	93	}
	94	ss->state \|= FIO_SS_BUFFER_FULL;
	95	} else { /* easy to update the sums */
	96	ss->sum_y -= ss->oldest_y;
	97	ss->sum_y += new_val;
	98	ss->sum_xy = ss->sum_xy - ss->sum_y + intervals * new_val;
	99	}
	100
	101	if (ss->state & FIO_SS_IOPS)
	102	ss->oldest_y = ss->iops_data[ss->head];
	103	else
	104	ss->oldest_y = ss->bw_data[ss->head];
	105
	106	/*
	107	* calculate slope as (sum_xy - sum_x * sum_y / n) / (sum_(x^2)
	108	* - (sum_x)^2 / n) This code assumes that all x values are
	109	* equally spaced when they are often off by a few milliseconds.
	110	* This assumption greatly simplifies the calculations.
	111	*/
	112	ss->slope = (ss->sum_xy - (double) ss->sum_x * ss->sum_y / intervals) /
	113	(ss->sum_x_sq - (double) ss->sum_x * ss->sum_x / intervals);
	114	if (ss->state & FIO_SS_PCT)
	115	ss->criterion = 100.0 * ss->slope / (ss->sum_y / intervals);
	116	else
	117	ss->criterion = ss->slope;
	118
	119	dprint(FD_STEADYSTATE, "sum_y: %llu, sum_xy: %llu, slope: %f, "
	120	"criterion: %f, limit: %f\n",
	121	(unsigned long long) ss->sum_y,
	122	(unsigned long long) ss->sum_xy,
	123	ss->slope, ss->criterion, ss->limit);
	124
	125	result = ss->criterion * (ss->criterion < 0.0 ? -1.0 : 1.0);
	126	if (result < ss->limit)
	127	return true;
	128	}
	129
	130	ss->tail = (ss->tail + 1) % intervals;
	131	if (ss->tail <= ss->head)
	132	ss->head = (ss->head + 1) % intervals;
	133
	134	return false;
	135	}
	136
	137	static bool steadystate_deviation(uint64_t iops, uint64_t bw,
	138	struct thread_data *td)
	139	{
	140	int i;
	141	double diff;
	142	double mean;
	143
	144	struct steadystate_data *ss = &td->ss;
	145	int intervals = ss->dur / (ss_check_interval / 1000L);
	146
	147	ss->bw_data[ss->tail] = bw;
	148	ss->iops_data[ss->tail] = iops;
	149
	150	if (ss->state & FIO_SS_BUFFER_FULL \|\| ss->tail - ss->head == intervals - 1) {
	151	if (!(ss->state & FIO_SS_BUFFER_FULL)) {
	152	/* first time through */
	153	for (i = 0, ss->sum_y = 0; i < intervals; i++) {
	154	if (ss->state & FIO_SS_IOPS)
	155	ss->sum_y += ss->iops_data[i];
	156	else
	157	ss->sum_y += ss->bw_data[i];
	158	}
	159	ss->state \|= FIO_SS_BUFFER_FULL;
	160	} else { /* easy to update the sum */
	161	ss->sum_y -= ss->oldest_y;
	162	if (ss->state & FIO_SS_IOPS)
	163	ss->sum_y += ss->iops_data[ss->tail];
	164	else
	165	ss->sum_y += ss->bw_data[ss->tail];
	166	}
	167
	168	if (ss->state & FIO_SS_IOPS)
	169	ss->oldest_y = ss->iops_data[ss->head];
	170	else
	171	ss->oldest_y = ss->bw_data[ss->head];
	172
	173	mean = (double) ss->sum_y / intervals;
	174	ss->deviation = 0.0;
	175
	176	for (i = 0; i < intervals; i++) {
	177	if (ss->state & FIO_SS_IOPS)
	178	diff = ss->iops_data[i] - mean;
	179	else
	180	diff = ss->bw_data[i] - mean;
	181	ss->deviation = max(ss->deviation, diff * (diff < 0.0 ? -1.0 : 1.0));
	182	}
	183
	184	if (ss->state & FIO_SS_PCT)
	185	ss->criterion = 100.0 * ss->deviation / mean;
	186	else
	187	ss->criterion = ss->deviation;
	188
	189	dprint(FD_STEADYSTATE, "intervals: %d, sum_y: %llu, mean: %f, max diff: %f, "
	190	"objective: %f, limit: %f\n",
	191	intervals,
	192	(unsigned long long) ss->sum_y, mean,
	193	ss->deviation, ss->criterion, ss->limit);
	194
	195	if (ss->criterion < ss->limit)
	196	return true;
	197	}
	198
	199	ss->tail = (ss->tail + 1) % intervals;
	200	if (ss->tail == ss->head)
	201	ss->head = (ss->head + 1) % intervals;
	202
	203	return false;
	204	}
	205
	206	int steadystate_check(void)
	207	{
	208	int ddir, prev_groupid, group_ramp_time_over = 0;
	209	unsigned long rate_time;
	210	struct timespec now;
	211	uint64_t group_bw = 0, group_iops = 0;
	212	uint64_t td_iops, td_bytes;
	213	bool ret;
	214
	215	prev_groupid = -1;
	216	for_each_td(td) {
	217	const bool needs_lock = td_async_processing(td);
	218	struct steadystate_data *ss = &td->ss;
	219
	220	if (!ss->dur \|\| td->runstate <= TD_SETTING_UP \|\|
	221	td->runstate >= TD_EXITED \|\| !ss->state \|\|
	222	ss->state & FIO_SS_ATTAINED)
	223	continue;
	224
	225	td_iops = 0;
	226	td_bytes = 0;
	227	if (!td->o.group_reporting \|\|
	228	(td->o.group_reporting && td->groupid != prev_groupid)) {
	229	group_bw = 0;
	230	group_iops = 0;
	231	group_ramp_time_over = 0;
	232	}
	233	prev_groupid = td->groupid;
	234
	235	fio_gettime(&now, NULL);
	236	if (ss->ramp_time && !(ss->state & FIO_SS_RAMP_OVER)) {
	237	/*
	238	* Begin recording data one check interval after ss->ramp_time
	239	* has elapsed
	240	*/
	241	if (utime_since(&td->epoch, &now) >= (ss->ramp_time + ss_check_interval * 1000L))
	242	ss->state \|= FIO_SS_RAMP_OVER;
	243	}
	244
	245	if (needs_lock)
	246	__td_io_u_lock(td);
	247
	248	for (ddir = 0; ddir < DDIR_RWDIR_CNT; ddir++) {
	249	td_iops += td->io_blocks[ddir];
	250	td_bytes += td->io_bytes[ddir];
	251	}
	252
	253	if (needs_lock)
	254	__td_io_u_unlock(td);
	255
	256	rate_time = mtime_since(&ss->prev_time, &now);
	257	memcpy(&ss->prev_time, &now, sizeof(now));
	258
	259	if (ss->state & FIO_SS_RAMP_OVER) {
	260	group_bw += rate_time * (td_bytes - ss->prev_bytes) /
	261	(ss_check_interval * ss_check_interval / 1000L);
	262	group_iops += rate_time * (td_iops - ss->prev_iops) /
	263	(ss_check_interval * ss_check_interval / 1000L);
	264	++group_ramp_time_over;
	265	}
	266	ss->prev_iops = td_iops;
	267	ss->prev_bytes = td_bytes;
	268
	269	if (td->o.group_reporting && !(ss->state & FIO_SS_DATA))
	270	continue;
	271
	272	/*
	273	* Don't begin checking criterion until ss->ramp_time is over
	274	* for at least one thread in group
	275	*/
	276	if (!group_ramp_time_over)
	277	continue;
	278
	279	dprint(FD_STEADYSTATE, "steadystate_check() thread: %d, "
	280	"groupid: %u, rate_msec: %ld, "
	281	"iops: %llu, bw: %llu, head: %d, tail: %d\n",
	282	__td_index, td->groupid, rate_time,
	283	(unsigned long long) group_iops,
	284	(unsigned long long) group_bw,
	285	ss->head, ss->tail);
	286
	287	if (ss->state & FIO_SS_SLOPE)
	288	ret = steadystate_slope(group_iops, group_bw, td);
	289	else
	290	ret = steadystate_deviation(group_iops, group_bw, td);
	291
	292	if (ret) {
	293	if (td->o.group_reporting) {
	294	for_each_td(td2) {
	295	if (td2->groupid == td->groupid) {
	296	td2->ss.state \|= FIO_SS_ATTAINED;
	297	fio_mark_td_terminate(td2);
	298	}
	299	} end_for_each();
	300	} else {
	301	ss->state \|= FIO_SS_ATTAINED;
	302	fio_mark_td_terminate(td);
	303	}
	304	}
	305	} end_for_each();
	306	return 0;
	307	}
	308
	309	int td_steadystate_init(struct thread_data *td)
	310	{
	311	struct steadystate_data *ss = &td->ss;
	312	struct thread_options *o = &td->o;
	313	int intervals;
	314
	315	memset(ss, 0, sizeof(*ss));
	316
	317	if (o->ss_dur) {
	318	steadystate_enabled = true;
	319	o->ss_dur /= 1000000L;
	320
	321	/* put all steady state info in one place */
	322	ss->dur = o->ss_dur;
	323	ss->limit = o->ss_limit.u.f;
	324	ss->ramp_time = o->ss_ramp_time;
	325	ss_check_interval = o->ss_check_interval / 1000L;
	326
	327	ss->state = o->ss_state;
	328	if (!td->ss.ramp_time)
	329	ss->state \|= FIO_SS_RAMP_OVER;
	330
	331	intervals = ss->dur / (ss_check_interval / 1000L);
	332	ss->sum_x = intervals * (intervals - 1) / 2;
	333	ss->sum_x_sq = (intervals - 1) * (intervals) * (2*intervals - 1) / 6;
	334	}
	335
	336	/* make sure that ss options are consistent within reporting group */
	337	for_each_td(td2) {
	338	if (td2->groupid == td->groupid) {
	339	struct steadystate_data *ss2 = &td2->ss;
	340
	341	if (ss2->dur != ss->dur \|\|
	342	ss2->limit != ss->limit \|\|
	343	ss2->ramp_time != ss->ramp_time \|\|
	344	ss2->state != ss->state \|\|
	345	ss2->sum_x != ss->sum_x \|\|
	346	ss2->sum_x_sq != ss->sum_x_sq) {
	347	td_verror(td, EINVAL, "job rejected: steadystate options must be consistent within reporting groups");
	348	return 1;
	349	}
	350	}
	351	} end_for_each();
	352
	353	return 0;
	354	}
	355
	356	uint64_t steadystate_bw_mean(struct thread_stat *ts)
	357	{
	358	int i;
	359	uint64_t sum;
	360	int intervals = ts->ss_dur / (ss_check_interval / 1000L);
	361
	362	if (!ts->ss_dur)
	363	return 0;
	364
	365	for (i = 0, sum = 0; i < intervals; i++)
	366	sum += ts->ss_bw_data[i];
	367
	368	return sum / intervals;
	369	}
	370
	371	uint64_t steadystate_iops_mean(struct thread_stat *ts)
	372	{
	373	int i;
	374	uint64_t sum;
	375	int intervals = ts->ss_dur / (ss_check_interval / 1000L);
	376
	377	if (!ts->ss_dur)
	378	return 0;
	379
	380	for (i = 0, sum = 0; i < intervals; i++)
	381	sum += ts->ss_iops_data[i];
	382
	383	return sum / intervals;
	384	}