From 6cd4d583c75042bf1edd3d2d5c6626883755bfe4 Mon Sep 17 00:00:00 2001
From: Vincent Fu <vincent.fu@sandisk.com>
Date: Fri, 3 Jun 2016 08:57:19 -0600
Subject: [PATCH] tools/fio_latency2csv.py: add tool that converts json+ to CSV

Signed-off-by: Jens Axboe <axboe@fb.com>
---
 Makefile                 |   2 +-
 tools/fio_latency2csv.py | 101 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 102 insertions(+), 1 deletion(-)
 create mode 100755 tools/fio_latency2csv.py

diff --git a/Makefile b/Makefile
index 108e6ee5..c617d6f4 100644
--- a/Makefile
+++ b/Makefile
@@ -26,7 +26,7 @@ OPTFLAGS= -g -ffast-math
 CFLAGS	= -std=gnu99 -Wwrite-strings -Wall -Wdeclaration-after-statement $(OPTFLAGS) $(EXTFLAGS) $(BUILD_CFLAGS) -I. -I$(SRCDIR)
 LIBS	+= -lm $(EXTLIBS)
 PROGS	= fio
-SCRIPTS = $(addprefix $(SRCDIR)/,tools/fio_generate_plots tools/plot/fio2gnuplot tools/genfio tools/fiologparser.py)
+SCRIPTS = $(addprefix $(SRCDIR)/,tools/fio_generate_plots tools/plot/fio2gnuplot tools/genfio tools/fiologparser.py tools/fio_latency2csv.py)
 
 ifndef CONFIG_FIO_NO_OPT
   CFLAGS += -O3
diff --git a/tools/fio_latency2csv.py b/tools/fio_latency2csv.py
new file mode 100755
index 00000000..93586d27
--- /dev/null
+++ b/tools/fio_latency2csv.py
@@ -0,0 +1,101 @@
+#!/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")
-- 
2.25.1