ceph/src/spdk/scripts/histogram.py

   1 #!/usr/bin/env python3
   2
   3 import sys
   4 import json
   5 import base64
   6 import struct
   7
   8 buf = sys.stdin.readlines()
   9 json = json.loads(" ".join(buf))
  10 histogram = base64.b64decode(json["histogram"])
  11 bucket_shift = json["bucket_shift"]
  12 tsc_rate = json["tsc_rate"]
  13
  14 print("Latency histogram")
  15 print("==============================================================================")
  16 print("       Range in us     Cumulative    IO count")
  17
  18 so_far = 0
  19 bucket = 0
  20 total = 1
  21
  22 for i in range(0, 64 - bucket_shift):
  23     for j in range(0, (1 << bucket_shift)):
  24         index = (((i << bucket_shift) + j) * 8)
  25         total += int.from_bytes(histogram[index:index + 8], 'little')
  26
  27 for i in range(0, 64 - bucket_shift):
  28     for j in range(0, (1 << bucket_shift)):
  29         index = (((i << bucket_shift) + j)*8)
  30         count = int.from_bytes(histogram[index:index + 8], 'little')
  31         so_far += count
  32         last_bucket = bucket
  33
  34         if i > 0:
  35             bucket = (1 << (i + bucket_shift - 1))
  36             bucket += ((j+1) << (i - 1))
  37         else:
  38             bucket = j+1
  39
  40         start = last_bucket * 1000 * 1000 / tsc_rate
  41         end = bucket * 1000 * 1000 / tsc_rate
  42         so_far_pct = so_far * 100.0 / total
  43         if count > 0:
  44             print("%9.3f - %9.3f: %9.4f%%  (%9u)" % (start, end, so_far_pct, count))