1#!/usr/bin/perl -w
2#
3# hotkernel - sample on-CPU kernel-level functions and modules.
4#             Written using Perl and DTrace (Solaris 10 03/05)
5#
6# This samples the on-CPU function at 1001 Hertz, for a simple yet
7# effective kernel-level profiling tool for sampling exclusive function time.
8# The output will identify which function is on the CPU the most - which is
9# the hottest. See Notes/ALLexclusive_notes.txt for an explanation of
10# exclusive time.
11#
12# $Id: hotkernel 65 2007-10-04 11:09:40Z brendan $
13#
14# USAGE:        hotkernel [-hm]
15#
16#		-h              # help
17#		-m              # match modules, not functions
18#       eg,
19#		hotkernel       # sample kernel functions
20#		hotkernel -m    # sample kernel modules
21#
22# FIELDS:
23#		FUNCTION        Function name
24#		MODULE          Module name
25#		COUNT           Number of samples
26#		PCNT            Percentage of total samples
27#
28# COPYRIGHT: Copyright (c) 2006 Brendan Gregg.
29#
30# CDDL HEADER START
31#
32#  The contents of this file are subject to the terms of the
33#  Common Development and Distribution License, Version 1.0 only
34#  (the "License").  You may not use this file except in compliance
35#  with the License.
36#
37#  You can obtain a copy of the license at Docs/cddl1.txt
38#  or http://www.opensolaris.org/os/licensing.
39#  See the License for the specific language governing permissions
40#  and limitations under the License.
41#
42# CDDL HEADER END
43#
44# Author: Brendan Gregg  [Sydney, Australia]
45#
46# 29-Jun-2006	Brendan Gregg	Created this.
47# 29-Jun-2006	   "      "	Last update.
48#
49
50use strict;
51use Getopt::Std;
52
53#
54# Command Line Arguments
55#
56my $args;
57usage() if defined $ARGV[0] and $ARGV[0] eq "--help";
58getopts('hm') or usage();
59usage() if defined $main::opt_h and $main::opt_h;
60my $mods = defined $main::opt_m and $main::opt_m ? 1 : 0;
61
62#
63# Cleanup on signals
64#
65$SIG{INT} = \&cleanupsig;    # Ctrl-C
66$SIG{QUIT} = \&cleanupsig;   # Ctrl-\
67$SIG{TERM} = \&cleanupsig;   # TERM
68
69#
70# Declare DTrace script
71#
72my $dtrace = <<END;
73/usr/sbin/dtrace -n '
74	#pragma D option quiet
75	profile:::profile-1001hz
76	/arg0/
77	{
78		\@pc[arg0] = count();
79	}
80	dtrace:::END
81	{
82		printa("%a %\@d\\n", \@pc);
83	}
84'
85END
86
87#
88# Run DTrace, process output
89#
90my %Count;
91my $total;
92open DTRACE, "$dtrace |" or die "ERROR1: Can't run dtrace (perms?): $!\n";
93print "Sampling... Hit Ctrl-C to end.\n";
94while (my $line = <DTRACE>) {
95    next if $line =~ /^\s*$/;
96    my ($addr, $count) = split ' ', $line;
97    my ($name, $offset) = split /\+/, $addr;
98    next if $name eq "0x0";
99    $name =~ s/\`.*// if $mods;
100    $Count{$name} += $count;
101    $total += $count;
102}
103close DTRACE;
104
105#
106# Print final report
107#
108printf "\n%-52s %8s %6s\n", $mods ? "MODULE" : "FUNCTION", "COUNT", "PCNT";
109foreach my $name (sort { $Count{$a} <=> $Count{$b} } keys %Count) {
110    printf "%-52s %8d %5.1f%%\n", $name, $Count{$name},
111                                  100 * $Count{$name} / ($total ? $total : 1);
112}
113
114#
115# Subroutines
116#
117sub cleanupsig {
118}
119sub usage {
120    print STDERR "USAGE: hotkernel [-hm]\n";
121    print STDERR "   eg,\n";
122    print STDERR "       hotkernel       # sample kernel functions\n";
123    print STDERR "       hotkernel -m    # sample kernel modules\n";
124    exit 1;
125}
126