--- /dev/null
+#!/usr/bin/python
+#
+# fio_latency2csv.py
+#
+# This tool converts fio's json+ completion latency data to CSV format.
+# For example:
+#
+# fio_latency2csv.py fio-jsonplus.output fio-latency.csv
+#
+
+import os
+import json
+import argparse
+
+
+def parse_args():
+ parser = argparse.ArgumentParser()
+ parser.add_argument('source',
+ help='fio json+ output file containing completion '
+ 'latency data')
+ parser.add_argument('dest',
+ help='destination file stub for latency data in CSV '
+ 'format. job number will be appended to filename')
+ args = parser.parse_args()
+
+ return args
+
+
+# from stat.c
+def plat_idx_to_val(idx, FIO_IO_U_PLAT_BITS=6, FIO_IO_U_PLAT_VAL=64):
+ # 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)):
+ return idx
+
+ # Find the group and compute the minimum value of that group
+ 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
+ k = idx % FIO_IO_U_PLAT_VAL
+
+ # Return the mean of the range of the bucket
+ return (base + ((k + 0.5) * (1 << error_bits)))
+
+
+def percentile(idx, run_total):
+ total = run_total[len(run_total)-1]
+ if total == 0:
+ return 0
+
+ return float(run_total[x]) / total
+
+
+if __name__ == '__main__':
+ args = parse_args()
+
+ with open(args.source, 'r') as source:
+ jsondata = json.loads(source.read())
+
+ bins = {}
+ bin_const = {}
+ run_total = {}
+ ddir_list = ['read', 'write', 'trim']
+ const_list = ['FIO_IO_U_PLAT_NR', 'FIO_IO_U_PLAT_BITS',
+ 'FIO_IO_U_PLAT_VAL']
+
+ for jobnum in range(0,len(jsondata['jobs'])):
+ prev_ddir = None
+ for ddir in ddir_list:
+ bins[ddir] = jsondata['jobs'][jobnum][ddir]['clat']['bins']
+
+ bin_const[ddir] = {}
+ for const in const_list:
+ bin_const[ddir][const] = bins[ddir].pop(const)
+ if prev_ddir:
+ assert bin_const[ddir][const] == bin_const[prev_ddir][const]
+ prev_ddir = ddir
+
+ run_total[ddir] = [0 for x in
+ range(bin_const[ddir]['FIO_IO_U_PLAT_NR'])]
+ run_total[ddir][0] = bins[ddir]['0']
+ for x in range(1, bin_const[ddir]['FIO_IO_U_PLAT_NR']):
+ run_total[ddir][x] = run_total[ddir][x-1] + bins[ddir][str(x)]
+
+ stub, ext = os.path.splitext(args.dest)
+ outfile = stub + '_job' + str(jobnum) + ext
+
+ with open(outfile, 'w') as output:
+ output.write("clat (usec),")
+ for ddir in ddir_list:
+ output.write("{0},".format(ddir))
+ output.write("\n")
+
+ for x in range(bin_const['read']['FIO_IO_U_PLAT_NR']):
+ output.write("{0},".format(plat_idx_to_val(x,
+ bin_const['read']['FIO_IO_U_PLAT_BITS'],
+ bin_const['read']['FIO_IO_U_PLAT_VAL'])))
+ for ddir in ddir_list:
+ output.write("{0},".format(percentile(x, run_total[ddir])))
+ output.write("\n")