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