tools/perf/scripts/python/net_dropmonitor.py

   1 # Monitor the system for dropped packets and proudce a report of drop locations and counts
   2 # SPDX-License-Identifier: GPL-2.0
   3
   4 import os
   5 import sys
   6
   7 sys.path.append(os.environ['PERF_EXEC_PATH'] + \
   8                 '/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
   9
  10 from perf_trace_context import *
  11 from Core import *
  12 from Util import *
  13
  14 drop_log = {}
  15 kallsyms = []
  16
  17 def get_kallsyms_table():
  18         global kallsyms
  19
  20         try:
  21                 f = open("/proc/kallsyms", "r")
  22         except:
  23                 return
  24
  25         for line in f:
  26                 loc = int(line.split()[0], 16)
  27                 name = line.split()[2]
  28                 kallsyms.append((loc, name))
  29         kallsyms.sort()
  30
  31 def get_sym(sloc):
  32         loc = int(sloc)
  33
  34         # Invariant: kallsyms[i][0] <= loc for all 0 <= i <= start
  35         #            kallsyms[i][0] > loc for all end <= i < len(kallsyms)
  36         start, end = -1, len(kallsyms)
  37         while end != start + 1:
  38                 pivot = (start + end) // 2
  39                 if loc < kallsyms[pivot][0]:
  40                         end = pivot
  41                 else:
  42                         start = pivot
  43
  44         # Now (start == -1 or kallsyms[start][0] <= loc)
  45         # and (start == len(kallsyms) - 1 or loc < kallsyms[start + 1][0])
  46         if start >= 0:
  47                 symloc, name = kallsyms[start]
  48                 return (name, loc - symloc)
  49         else:
  50                 return (None, 0)
  51
  52 def print_drop_table():
  53         print "%25s %25s %25s" % ("LOCATION", "OFFSET", "COUNT")
  54         for i in drop_log.keys():
  55                 (sym, off) = get_sym(i)
  56                 if sym == None:
  57                         sym = i
  58                 print "%25s %25s %25s" % (sym, off, drop_log[i])
  59
  60
  61 def trace_begin():
  62         print "Starting trace (Ctrl-C to dump results)"
  63
  64 def trace_end():
  65         print "Gathering kallsyms data"
  66         get_kallsyms_table()
  67         print_drop_table()
  68
  69 # called from perf, when it finds a correspoinding event
  70 def skb__kfree_skb(name, context, cpu, sec, nsec, pid, comm, callchain,
  71                    skbaddr, location, protocol):
  72         slocation = str(location)
  73         try:
  74                 drop_log[slocation] = drop_log[slocation] + 1
  75         except:
  76                 drop_log[slocation] = 1