X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=stat.c;h=ee495ffd88dc5dae82f92717deda18e59ef8bd57;hp=19b36961aa4854f0e3fb27a692b04ed5f52cb9e9;hb=fb390e242cac8868e01cdc2046c63e04e3d53d70;hpb=72c27ff8f2eaf945ae34776dab4da3fee753707d

diff --git a/stat.c b/stat.c
index 19b36961..ee495ffd 100644
--- a/stat.c
+++ b/stat.c
@@ -63,12 +63,12 @@ static unsigned int plat_val_to_idx(unsigned int val)
 
 	/*
 	 * Discard the error bits and apply the mask to find the
-         * index for the buckets in the group
+	 * index for the buckets in the group
 	 */
 	offset = (FIO_IO_U_PLAT_VAL - 1) & (val >> error_bits);
 
 	/* Make sure the index does not exceed (array size - 1) */
-	idx = (base + offset) < (FIO_IO_U_PLAT_NR - 1)?
+	idx = (base + offset) < (FIO_IO_U_PLAT_NR - 1) ?
 		(base + offset) : (FIO_IO_U_PLAT_NR - 1);
 
 	return idx;
@@ -86,11 +86,11 @@ static unsigned int plat_idx_to_val(unsigned int idx)
 
 	/* MSB <= (FIO_IO_U_PLAT_BITS-1), cannot be rounded off. Use
 	 * all bits of the sample as index */
-	if (idx < (FIO_IO_U_PLAT_VAL << 1) )
+	if (idx < (FIO_IO_U_PLAT_VAL << 1))
 		return idx;
 
 	/* Find the group and compute the minimum value of that group */
-	error_bits = (idx >> FIO_IO_U_PLAT_BITS) -1;
+	error_bits = (idx >> FIO_IO_U_PLAT_BITS) - 1;
 	base = 1 << (error_bits + FIO_IO_U_PLAT_BITS);
 
 	/* Find its bucket number of the group */
@@ -114,11 +114,9 @@ static int double_cmp(const void *a, const void *b)
 	return cmp;
 }
 
-static unsigned int calc_clat_percentiles(unsigned int *io_u_plat,
-					  unsigned long nr, fio_fp64_t *plist,
-					  unsigned int **output,
-					  unsigned int *maxv,
-					  unsigned int *minv)
+unsigned int calc_clat_percentiles(unsigned int *io_u_plat, unsigned long nr,
+				   fio_fp64_t *plist, unsigned int **output,
+				   unsigned int *maxv, unsigned int *minv)
 {
 	unsigned long sum = 0;
 	unsigned int len, i, j = 0;
@@ -142,7 +140,7 @@ static unsigned int calc_clat_percentiles(unsigned int *io_u_plat,
 	 * isn't a worry. Also note that this does not work for NaN values.
 	 */
 	if (len > 1)
-		qsort((void*)plist, len, sizeof(plist[0]), double_cmp);
+		qsort((void *)plist, len, sizeof(plist[0]), double_cmp);
 
 	/*
 	 * Calculate bucket values, note down max and min values
@@ -234,8 +232,8 @@ out:
 		free(ovals);
 }
 
-static int calc_lat(struct io_stat *is, unsigned long *min, unsigned long *max,
-		    double *mean, double *dev)
+int calc_lat(struct io_stat *is, unsigned long *min, unsigned long *max,
+	     double *mean, double *dev)
 {
 	double n = is->samples;
 
@@ -287,11 +285,7 @@ void show_group_stats(struct group_run_stats *rs)
 	}
 }
 
-#define ts_total_io_u(ts)	\
-	((ts)->total_io_u[0] + (ts)->total_io_u[1])
-
-static void stat_calc_dist(unsigned int *map, unsigned long total,
-			   double *io_u_dist)
+void stat_calc_dist(unsigned int *map, unsigned long total, double *io_u_dist)
 {
 	int i;
 
@@ -329,28 +323,33 @@ static void stat_calc_lat(struct thread_stat *ts, double *dst,
 	}
 }
 
-static void stat_calc_lat_u(struct thread_stat *ts, double *io_u_lat)
+void stat_calc_lat_u(struct thread_stat *ts, double *io_u_lat)
 {
 	stat_calc_lat(ts, io_u_lat, ts->io_u_lat_u, FIO_IO_U_LAT_U_NR);
 }
 
-static void stat_calc_lat_m(struct thread_stat *ts, double *io_u_lat)
+void stat_calc_lat_m(struct thread_stat *ts, double *io_u_lat)
 {
 	stat_calc_lat(ts, io_u_lat, ts->io_u_lat_m, FIO_IO_U_LAT_M_NR);
 }
 
-static int usec_to_msec(unsigned long *min, unsigned long *max, double *mean,
-			double *dev)
+static void display_lat(const char *name, unsigned long min, unsigned long max,
+			double mean, double dev)
 {
-	if (*min > 1000 && *max > 1000 && *mean > 1000.0 && *dev > 1000.0) {
-		*min /= 1000;
-		*max /= 1000;
-		*mean /= 1000.0;
-		*dev /= 1000.0;
-		return 0;
-	}
+	const char *base = "(usec)";
+	char *minp, *maxp;
 
-	return 1;
+	if (!usec_to_msec(&min, &max, &mean, &dev))
+		base = "(msec)";
+
+	minp = num2str(min, 6, 1, 0);
+	maxp = num2str(max, 6, 1, 0);
+
+	log_info("    %s %s: min=%s, max=%s, avg=%5.02f,"
+		 " stdev=%5.02f\n", name, base, minp, maxp, mean, dev);
+
+	free(minp);
+	free(maxp);
 }
 
 static void show_ddir_status(struct group_run_stats *rs, struct thread_stat *ts,
@@ -386,66 +385,27 @@ static void show_ddir_status(struct group_run_stats *rs, struct thread_stat *ts,
 	free(bw_p);
 	free(iops_p);
 
-	if (calc_lat(&ts->slat_stat[ddir], &min, &max, &mean, &dev)) {
-		const char *base = "(usec)";
-		char *minp, *maxp;
-
-		if (!usec_to_msec(&min, &max, &mean, &dev))
-			base = "(msec)";
-
-		minp = num2str(min, 6, 1, 0);
-		maxp = num2str(max, 6, 1, 0);
-
-		log_info("    slat %s: min=%s, max=%s, avg=%5.02f,"
-			 " stdev=%5.02f\n", base, minp, maxp, mean, dev);
-
-		free(minp);
-		free(maxp);
-	}
-	if (calc_lat(&ts->clat_stat[ddir], &min, &max, &mean, &dev)) {
-		const char *base = "(usec)";
-		char *minp, *maxp;
-
-		if (!usec_to_msec(&min, &max, &mean, &dev))
-			base = "(msec)";
-
-		minp = num2str(min, 6, 1, 0);
-		maxp = num2str(max, 6, 1, 0);
-
-		log_info("    clat %s: min=%s, max=%s, avg=%5.02f,"
-			 " stdev=%5.02f\n", base, minp, maxp, mean, dev);
-
-		free(minp);
-		free(maxp);
-	}
-	if (calc_lat(&ts->lat_stat[ddir], &min, &max, &mean, &dev)) {
-		const char *base = "(usec)";
-		char *minp, *maxp;
-
-		if (!usec_to_msec(&min, &max, &mean, &dev))
-			base = "(msec)";
-
-		minp = num2str(min, 6, 1, 0);
-		maxp = num2str(max, 6, 1, 0);
-
-		log_info("     lat %s: min=%s, max=%s, avg=%5.02f,"
-			 " stdev=%5.02f\n", base, minp, maxp, mean, dev);
+	if (calc_lat(&ts->slat_stat[ddir], &min, &max, &mean, &dev))
+		display_lat("slat", min, max, mean, dev);
+	if (calc_lat(&ts->clat_stat[ddir], &min, &max, &mean, &dev))
+		display_lat("clat", min, max, mean, dev);
+	if (calc_lat(&ts->lat_stat[ddir], &min, &max, &mean, &dev))
+		display_lat(" lat", min, max, mean, dev);
 
-		free(minp);
-		free(maxp);
-	}
 	if (ts->clat_percentiles) {
 		show_clat_percentiles(ts->io_u_plat[ddir],
 					ts->clat_stat[ddir].samples,
 					ts->percentile_list);
 	}
 	if (calc_lat(&ts->bw_stat[ddir], &min, &max, &mean, &dev)) {
-		double p_of_agg;
+		double p_of_agg = 100.0;
 		const char *bw_str = "KB";
 
-		p_of_agg = mean * 100 / (double) rs->agg[ddir];
-		if (p_of_agg > 100.0)
-			p_of_agg = 100.0;
+		if (rs->agg[ddir]) {
+			p_of_agg = mean * 100 / (double) rs->agg[ddir];
+			if (p_of_agg > 100.0)
+				p_of_agg = 100.0;
+		}
 
 		if (mean > 999999.9) {
 			min /= 1000.0;
@@ -508,8 +468,14 @@ static void show_lat_m(double *io_u_lat_m)
 	show_lat(io_u_lat_m, FIO_IO_U_LAT_M_NR, ranges, "msec");
 }
 
-static void show_latencies(double *io_u_lat_u, double *io_u_lat_m)
+static void show_latencies(struct thread_stat *ts)
 {
+	double io_u_lat_u[FIO_IO_U_LAT_U_NR];
+	double io_u_lat_m[FIO_IO_U_LAT_M_NR];
+
+	stat_calc_lat_u(ts, io_u_lat_u);
+	stat_calc_lat_m(ts, io_u_lat_m);
+
 	show_lat_u(io_u_lat_u);
 	show_lat_m(io_u_lat_m);
 }
@@ -519,8 +485,6 @@ void show_thread_status(struct thread_stat *ts, struct group_run_stats *rs)
 	double usr_cpu, sys_cpu;
 	unsigned long runtime;
 	double io_u_dist[FIO_IO_U_MAP_NR];
-	double io_u_lat_u[FIO_IO_U_LAT_U_NR];
-	double io_u_lat_m[FIO_IO_U_LAT_M_NR];
 
 	if (!(ts->io_bytes[0] + ts->io_bytes[1]) &&
 	    !(ts->total_io_u[0] + ts->total_io_u[1]))
@@ -544,9 +508,7 @@ void show_thread_status(struct thread_stat *ts, struct group_run_stats *rs)
 	if (ts->io_bytes[DDIR_WRITE])
 		show_ddir_status(rs, ts, DDIR_WRITE);
 
-	stat_calc_lat_u(ts, io_u_lat_u);
-	stat_calc_lat_m(ts, io_u_lat_m);
-	show_latencies(io_u_lat_u, io_u_lat_m);
+	show_latencies(ts);
 
 	runtime = ts->total_run_time;
 	if (runtime) {
@@ -611,7 +573,7 @@ static void show_ddir_status_terse(struct thread_stat *ts,
 	if (ts->runtime[ddir]) {
 		uint64_t runt = ts->runtime[ddir];
 
-		bw = ts->io_bytes[ddir] / runt;
+		bw = ((1000 * ts->io_bytes[ddir]) / runt) / 1024;
 		iops = (1000 * (uint64_t) ts->total_io_u[ddir]) / runt;
 	}
 
@@ -628,11 +590,6 @@ static void show_ddir_status_terse(struct thread_stat *ts,
 	else
 		log_info(";%lu;%lu;%f;%f", 0UL, 0UL, 0.0, 0.0);
 
-	if (calc_lat(&ts->lat_stat[ddir], &min, &max, &mean, &dev))
-		log_info(";%lu;%lu;%f;%f", min, max, mean, dev);
-	else
-		log_info(";%lu;%lu;%f;%f", 0UL, 0UL, 0.0, 0.0);
-
 	if (ts->clat_percentiles) {
 		len = calc_clat_percentiles(ts->io_u_plat[ddir],
 					ts->clat_stat[ddir].samples,
@@ -648,22 +605,91 @@ static void show_ddir_status_terse(struct thread_stat *ts,
 		}
 		log_info(";%2.2f%%=%u", ts->percentile_list[i].u.f, ovals[i]);
 	}
+
+	if (calc_lat(&ts->lat_stat[ddir], &min, &max, &mean, &dev))
+		log_info(";%lu;%lu;%f;%f", min, max, mean, dev);
+	else
+		log_info(";%lu;%lu;%f;%f", 0UL, 0UL, 0.0, 0.0);
+
 	if (ovals)
 		free(ovals);
 
 	if (calc_lat(&ts->bw_stat[ddir], &min, &max, &mean, &dev)) {
-		double p_of_agg;
+		double p_of_agg = 100.0;
+
+		if (rs->agg[ddir]) {
+			p_of_agg = mean * 100 / (double) rs->agg[ddir];
+			if (p_of_agg > 100.0)
+				p_of_agg = 100.0;
+		}
 
-		p_of_agg = mean * 100 / (double) rs->agg[ddir];
 		log_info(";%lu;%lu;%f%%;%f;%f", min, max, p_of_agg, mean, dev);
 	} else
 		log_info(";%lu;%lu;%f%%;%f;%f", 0UL, 0UL, 0.0, 0.0, 0.0);
 }
 
+static void show_thread_status_terse_v2(struct thread_stat *ts,
+					struct group_run_stats *rs)
+{
+	double io_u_dist[FIO_IO_U_MAP_NR];
+	double io_u_lat_u[FIO_IO_U_LAT_U_NR];
+	double io_u_lat_m[FIO_IO_U_LAT_M_NR];
+	double usr_cpu, sys_cpu;
+	int i;
+
+	/* General Info */
+	log_info("2;%s;%d;%d", ts->name, ts->groupid, ts->error);
+	/* Log Read Status */
+	show_ddir_status_terse(ts, rs, 0);
+	/* Log Write Status */
+	show_ddir_status_terse(ts, rs, 1);
+
+	/* CPU Usage */
+	if (ts->total_run_time) {
+		double runt = (double) ts->total_run_time;
+
+		usr_cpu = (double) ts->usr_time * 100 / runt;
+		sys_cpu = (double) ts->sys_time * 100 / runt;
+	} else {
+		usr_cpu = 0;
+		sys_cpu = 0;
+	}
+
+	log_info(";%f%%;%f%%;%lu;%lu;%lu", usr_cpu, sys_cpu, ts->ctx, ts->majf,
+								ts->minf);
+
+	/* Calc % distribution of IO depths, usecond, msecond latency */
+	stat_calc_dist(ts->io_u_map, ts_total_io_u(ts), io_u_dist);
+	stat_calc_lat_u(ts, io_u_lat_u);
+	stat_calc_lat_m(ts, io_u_lat_m);
+
+	/* Only show fixed 7 I/O depth levels*/
+	log_info(";%3.1f%%;%3.1f%%;%3.1f%%;%3.1f%%;%3.1f%%;%3.1f%%;%3.1f%%",
+			io_u_dist[0], io_u_dist[1], io_u_dist[2], io_u_dist[3],
+			io_u_dist[4], io_u_dist[5], io_u_dist[6]);
+
+	/* Microsecond latency */
+	for (i = 0; i < FIO_IO_U_LAT_U_NR; i++)
+		log_info(";%3.2f%%", io_u_lat_u[i]);
+	/* Millisecond latency */
+	for (i = 0; i < FIO_IO_U_LAT_M_NR; i++)
+		log_info(";%3.2f%%", io_u_lat_m[i]);
+	/* Additional output if continue_on_error set - default off*/
+	if (ts->continue_on_error)
+		log_info(";%lu;%d", ts->total_err_count, ts->first_error);
+	log_info("\n");
+
+	/* Additional output if description is set */
+	if (ts->description)
+		log_info(";%s", ts->description);
+
+	log_info("\n");
+}
+
 #define FIO_TERSE_VERSION	"3"
 
-static void show_thread_status_terse(struct thread_stat *ts,
-				     struct group_run_stats *rs)
+static void show_thread_status_terse_v3(struct thread_stat *ts,
+					struct group_run_stats *rs)
 {
 	double io_u_dist[FIO_IO_U_MAP_NR];
 	double io_u_lat_u[FIO_IO_U_LAT_U_NR];
@@ -716,11 +742,23 @@ static void show_thread_status_terse(struct thread_stat *ts,
 	/* Additional output if continue_on_error set - default off*/
 	if (ts->continue_on_error)
 		log_info(";%lu;%d", ts->total_err_count, ts->first_error);
-	log_info("\n");
 
 	/* Additional output if description is set */
 	if (strlen(ts->description))
 		log_info(";%s", ts->description);
+
+	log_info("\n");
+}
+
+static void show_thread_status_terse(struct thread_stat *ts,
+				     struct group_run_stats *rs)
+{
+	if (terse_version == 2)
+		show_thread_status_terse_v2(ts, rs);
+	else if (terse_version == 3)
+		show_thread_status_terse_v3(ts, rs);
+	else
+		log_err("fio: bad terse version!? %d\n", terse_version);
 }
 
 static void sum_stat(struct io_stat *dst, struct io_stat *src, int nr)
@@ -919,6 +957,11 @@ void show_run_stats(void)
 			else
 				memset(ts->description, 0, FIO_JOBNAME_SIZE);
 
+			/*
+			 * If multiple entries in this group, this is
+			 * the first member.
+			 */
+			ts->thread_number = td->thread_number;
 			ts->groupid = td->groupid;
 
 			/*
@@ -967,10 +1010,11 @@ void show_run_stats(void)
 
 			bw = 0;
 			if (ts->runtime[j]) {
-				unsigned long runt;
+				unsigned long runt = ts->runtime[j];
+				unsigned long long kb;
 
-				runt = ts->runtime[j];
-				bw = ts->io_bytes[j] / runt;
+				kb = ts->io_bytes[j] / rs->kb_base;
+				bw = kb * 1000 / runt;
 			}
 			if (bw < rs->min_bw[j])
 				rs->min_bw[j] = bw;
@@ -982,16 +1026,12 @@ void show_run_stats(void)
 	}
 
 	for (i = 0; i < groupid + 1; i++) {
-		unsigned long max_run[2];
-
 		rs = &runstats[i];
-		max_run[0] = rs->max_run[0];
-		max_run[1] = rs->max_run[1];
 
 		if (rs->max_run[0])
-			rs->agg[0] = (rs->io_kb[0] * 1000) / max_run[0];
+			rs->agg[0] = (rs->io_kb[0] * 1000) / rs->max_run[0];
 		if (rs->max_run[1])
-			rs->agg[1] = (rs->io_kb[1] * 1000) / max_run[1];
+			rs->agg[1] = (rs->io_kb[1] * 1000) / rs->max_run[1];
 	}
 
 	/*
@@ -1027,12 +1067,59 @@ void show_run_stats(void)
 	else if (!terse_output)
 		show_disk_util(0);
 
-	free_disk_util();
-
 	free(runstats);
 	free(threadstats);
 }
 
+static void *__show_running_run_stats(void *arg)
+{
+	struct thread_data *td;
+	unsigned long long *rt;
+	struct timeval tv;
+	int i;
+
+	rt = malloc(thread_number * sizeof(unsigned long long));
+	fio_gettime(&tv, NULL);
+
+	for_each_td(td, i) {
+		rt[i] = mtime_since(&td->start, &tv);
+		if (td_read(td) && td->io_bytes[DDIR_READ])
+			td->ts.runtime[DDIR_READ] += rt[i];
+		if (td_write(td) && td->io_bytes[DDIR_WRITE])
+			td->ts.runtime[DDIR_WRITE] += rt[i];
+
+		update_rusage_stat(td);
+		td->ts.io_bytes[0] = td->io_bytes[0];
+		td->ts.io_bytes[1] = td->io_bytes[1];
+		td->ts.total_run_time = mtime_since(&td->epoch, &tv);
+	}
+
+	show_run_stats();
+
+	for_each_td(td, i) {
+		if (td_read(td) && td->io_bytes[DDIR_READ])
+			td->ts.runtime[DDIR_READ] -= rt[i];
+		if (td_write(td) && td->io_bytes[DDIR_WRITE])
+			td->ts.runtime[DDIR_WRITE] -= rt[i];
+	}
+
+	free(rt);
+	return NULL;
+}
+
+/*
+ * Called from signal handler. It _should_ be safe to just run this inline
+ * in the sig handler, but we should be disturbing the system less by just
+ * creating a thread to do it.
+ */
+void show_running_run_stats(void)
+{
+	pthread_t thread;
+
+	pthread_create(&thread, NULL, __show_running_run_stats, NULL);
+	pthread_detach(thread);
+}
+
 static inline void add_stat_sample(struct io_stat *is, unsigned long data)
 {
 	double val = data;
@@ -1058,6 +1145,9 @@ static void __add_log_sample(struct io_log *iolog, unsigned long val,
 {
 	const int nr_samples = iolog->nr_samples;
 
+	if (!iolog->nr_samples)
+		iolog->avg_last = t;
+
 	if (iolog->nr_samples == iolog->max_samples) {
 		int new_size = sizeof(struct io_sample) * iolog->max_samples*2;
 
@@ -1072,14 +1162,66 @@ static void __add_log_sample(struct io_log *iolog, unsigned long val,
 	iolog->nr_samples++;
 }
 
+static inline void reset_io_stat(struct io_stat *ios)
+{
+	ios->max_val = ios->min_val = ios->samples = 0;
+	ios->mean.u.f = ios->S.u.f = 0;
+}
+
 static void add_log_sample(struct thread_data *td, struct io_log *iolog,
 			   unsigned long val, enum fio_ddir ddir,
 			   unsigned int bs)
 {
+	unsigned long elapsed, this_window;
+
 	if (!ddir_rw(ddir))
 		return;
 
-	__add_log_sample(iolog, val, ddir, bs, mtime_since_now(&td->epoch));
+	elapsed = mtime_since_now(&td->epoch);
+
+	/*
+	 * If no time averaging, just add the log sample.
+	 */
+	if (!iolog->avg_msec) {
+		__add_log_sample(iolog, val, ddir, bs, elapsed);
+		return;
+	}
+
+	/*
+	 * Add the sample. If the time period has passed, then
+	 * add that entry to the log and clear.
+	 */
+	add_stat_sample(&iolog->avg_window[ddir], val);
+
+	/*
+	 * If period hasn't passed, adding the above sample is all we
+	 * need to do.
+	 */
+	this_window = elapsed - iolog->avg_last;
+	if (this_window < iolog->avg_msec)
+		return;
+
+	/*
+	 * Note an entry in the log. Use the mean from the logged samples,
+	 * making sure to properly round up. Only write a log entry if we
+	 * had actual samples done.
+	 */
+	if (iolog->avg_window[DDIR_READ].samples) {
+		unsigned long mr;
+
+		mr = iolog->avg_window[DDIR_READ].mean.u.f + 0.50;
+		__add_log_sample(iolog, mr, DDIR_READ, 0, elapsed);
+	}
+	if (iolog->avg_window[DDIR_WRITE].samples) {
+		unsigned long mw;
+
+		mw = iolog->avg_window[DDIR_WRITE].mean.u.f + 0.50;
+		__add_log_sample(iolog, mw, DDIR_WRITE, 0, elapsed);
+	}
+
+	reset_io_stat(&iolog->avg_window[DDIR_READ]);
+	reset_io_stat(&iolog->avg_window[DDIR_WRITE]);
+	iolog->avg_last = elapsed;
 }
 
 void add_agg_sample(unsigned long val, enum fio_ddir ddir, unsigned int bs)
@@ -1160,15 +1302,26 @@ void add_bw_sample(struct thread_data *td, enum fio_ddir ddir, unsigned int bs,
 	if (spent < td->o.bw_avg_time)
 		return;
 
-	rate = (td->this_io_bytes[ddir] - td->stat_io_bytes[ddir]) *
-			1000 / spent / 1024;
-	add_stat_sample(&ts->bw_stat[ddir], rate);
+	/*
+	 * Compute both read and write rates for the interval.
+	 */
+	for (ddir = DDIR_READ; ddir <= DDIR_WRITE; ddir++) {
+		uint64_t delta;
+
+		delta = td->this_io_bytes[ddir] - td->stat_io_bytes[ddir];
+		if (!delta)
+			continue; /* No entries for interval */
+
+		rate = delta * 1000 / spent / 1024;
+		add_stat_sample(&ts->bw_stat[ddir], rate);
+
+		if (td->bw_log)
+			add_log_sample(td, td->bw_log, rate, ddir, bs);
 
-	if (td->bw_log)
-		add_log_sample(td, td->bw_log, rate, ddir, bs);
+		td->stat_io_bytes[ddir] = td->this_io_bytes[ddir];
+	}
 
 	fio_gettime(&td->bw_sample_time, NULL);
-	td->stat_io_bytes[ddir] = td->this_io_bytes[ddir];
 }
 
 void add_iops_sample(struct thread_data *td, enum fio_ddir ddir,
@@ -1184,15 +1337,24 @@ void add_iops_sample(struct thread_data *td, enum fio_ddir ddir,
 	if (spent < td->o.iops_avg_time)
 		return;
 
-	iops = ((td->this_io_blocks[ddir] - td->stat_io_blocks[ddir]) * 1000) / spent;
+	/*
+	 * Compute both read and write rates for the interval.
+	 */
+	for (ddir = DDIR_READ; ddir <= DDIR_WRITE; ddir++) {
+		uint64_t delta;
+
+		delta = td->this_io_blocks[ddir] - td->stat_io_blocks[ddir];
+		if (!delta)
+			continue; /* No entries for interval */
+
+		iops = (delta * 1000) / spent;
+		add_stat_sample(&ts->iops_stat[ddir], iops);
 
-	add_stat_sample(&ts->iops_stat[ddir], iops);
+		if (td->iops_log)
+			add_log_sample(td, td->iops_log, iops, ddir, 0);
 
-	if (td->iops_log) {
-		assert(iops);
-		add_log_sample(td, td->iops_log, iops, ddir, 0);
+		td->stat_io_blocks[ddir] = td->this_io_blocks[ddir];
 	}
 
 	fio_gettime(&td->iops_sample_time, NULL);
-	td->stat_io_blocks[ddir] = td->this_io_blocks[ddir];
 }