perf script: Add drop monitor script

#!/bin/bash

perf record -e skb:kfree_skb $@

#!/bin/bash

# description: display a table of dropped frames

perf script -s "$PERF_EXEC_PATH"/scripts/python/net_dropmonitor.py $@

# Monitor the system for dropped packets and proudce a report of drop locations and counts

import os

import sys

sys.path.append(os.environ['PERF_EXEC_PATH'] + \

		'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')

from perf_trace_context import *

from Core import *

from Util import *

drop_log = {}

kallsyms = []

def get_kallsyms_table():

	global kallsyms

	try:

		f = open("/proc/kallsyms", "r")

		linecount = 0

		for line in f:

			linecount = linecount+1

		f.seek(0)

	except:

		return

	j = 0

	for line in f:

		loc = int(line.split()[0], 16)

		name = line.split()[2]

		j = j +1

		if ((j % 100) == 0):

			print "\r" + str(j) + "/" + str(linecount),

		kallsyms.append({ 'loc': loc, 'name' : name})

	print "\r" + str(j) + "/" + str(linecount)

	kallsyms.sort()

	return

def get_sym(sloc):

	loc = int(sloc)

	for i in kallsyms:

		if (i['loc'] >= loc):

			return (i['name'], i['loc']-loc)

	return (None, 0)

def print_drop_table():

	print "%25s %25s %25s" % ("LOCATION", "OFFSET", "COUNT")

	for i in drop_log.keys():

		(sym, off) = get_sym(i)

		if sym == None:

			sym = i

		print "%25s %25s %25s" % (sym, off, drop_log[i])

def trace_begin():

	print "Starting trace (Ctrl-C to dump results)"

def trace_end():

	print "Gathering kallsyms data"

	get_kallsyms_table()

	print_drop_table()

# called from perf, when it finds a correspoinding event

def skb__kfree_skb(name, context, cpu, sec, nsec, pid, comm,

			skbaddr, protocol, location):

	slocation = str(location)

	try:

		drop_log[slocation] = drop_log[slocation] + 1

	except:

		drop_log[slocation] = 1