td->usr_time += mtime_since(&td->ru_start.ru_utime, &td->ru_end.ru_utime);
td->sys_time += mtime_since(&td->ru_start.ru_stime, &td->ru_end.ru_stime);
td->ctx += td->ru_end.ru_nvcsw + td->ru_end.ru_nivcsw - (td->ru_start.ru_nvcsw + td->ru_start.ru_nivcsw);
-
memcpy(&td->ru_start, &td->ru_end, sizeof(td->ru_end));
}
static int calc_lat(struct io_stat *is, unsigned long *min, unsigned long *max,
double *mean, double *dev)
{
- double n, o;
+ double n = is->samples;
if (is->samples == 0)
return 0;
*max = is->max_val;
n = (double) is->samples;
- *mean = (double) is->val / n;
- *dev = 0.01;
-
- if (n <= 1.0)
- return 1;
+ *mean = is->mean;
- o = ((double) is->val_sq - (*mean * is->val)) / n;
- if (o < 0.0)
- *dev = -1.0;
+ if (n > 1.0)
+ *dev = sqrt(is->S / (n - 1.0));
else
- *dev = sqrt(o);
+ *dev = -1.0;
return 1;
}
fprintf(f_out, " %s: io=%6lluMiB, bw=%6lluKiB/s, runt=%6lumsec\n", ddir_str[ddir], td->io_bytes[ddir] >> 20, bw, td->runtime[ddir]);
if (calc_lat(&td->slat_stat[ddir], &min, &max, &mean, &dev))
- fprintf(f_out, " slat (msec): min=%5lu, max=%5lu, avg=%5.02f, dev=%5.02f\n", min, max, mean, dev);
+ fprintf(f_out, " slat (msec): min=%5lu, max=%5lu, avg=%5.02f, stdev=%5.02f\n", min, max, mean, dev);
if (calc_lat(&td->clat_stat[ddir], &min, &max, &mean, &dev))
- fprintf(f_out, " clat (msec): min=%5lu, max=%5lu, avg=%5.02f, dev=%5.02f\n", min, max, mean, dev);
+ fprintf(f_out, " clat (msec): min=%5lu, max=%5lu, avg=%5.02f, stdev=%5.02f\n", min, max, mean, dev);
if (calc_lat(&td->bw_stat[ddir], &min, &max, &mean, &dev)) {
double p_of_agg;
p_of_agg = mean * 100 / (double) rs->agg[ddir];
- fprintf(f_out, " bw (KiB/s) : min=%5lu, max=%5lu, per=%3.2f%%, avg=%5.02f, dev=%5.02f\n", min, max, p_of_agg, mean, dev);
+ fprintf(f_out, " bw (KiB/s) : min=%5lu, max=%5lu, per=%3.2f%%, avg=%5.02f, stdev=%5.02f\n", min, max, p_of_agg, mean, dev);
}
}
free(runstats);
}
-static inline void add_stat_sample(struct io_stat *is, unsigned long val)
+static inline void add_stat_sample(struct io_stat *is, unsigned long data)
{
- if (val > is->max_val)
- is->max_val = val;
- if (val < is->min_val)
- is->min_val = val;
+ double val = data;
+ double delta, n;
+
+ if (data > is->max_val)
+ is->max_val = data;
+ if (data < is->min_val)
+ is->min_val = data;
+
+ delta = val - is->mean;
+ n = is->samples + 1.0;
+ is->mean += delta / n;
+ is->S += delta * (val - is->mean);
- is->val += val;
- is->val_sq += val * val;
is->samples++;
}