1#!/usr/sbin/dtrace -CZs
2/*
3 * j_profile.d - sample stack traces with Java translations using DTrace.
4 *
5 * USAGE: j_profile.d { -p PID | -c cmd }	# hit Ctrl-C to end
6 * $Id: j_profile.d 19 2007-09-12 07:47:59Z brendan $
7 *
8 *
9 * This samples stack traces for the process specified. This stack trace
10 * will cross the JVM and system libraries, and insert translations for Java
11 * stack frames where appropriate. This is best explained with an example
12 * stack frame output,
13 *
14 *            Func_loop.func_c()V
15 *            Func_loop.func_b()V
16 *            Func_loop.func_a()V
17 *            Func_loop.main([Ljava/lang/String;)V
18 *            StubRoutines (1)
19 *            libjvm.so`__1cJJavaCallsLcall_helper6FpnJJavaValue_pnMmethodHan
20 *            libjvm.so`__1cCosUos_exception_wrapper6FpFpnJJavaValue_pnMmetho
21 *            libjvm.so`__1cJJavaCallsEcall6FpnJJavaValue_nMmethodHandle_pnRJ
22 *            libjvm.so`__1cRjni_invoke_static6FpnHJNIEnv__pnJJavaValue_pnI_j
23 *            libjvm.so`jni_CallStaticVoidMethod+0x15d
24 *            java`JavaMain+0xd30
25 *            libc.so.1`_thr_setup+0x52
26 *            libc.so.1`_lwp_start
27 *            101
28 *
29 * The lines at the top are Java frames, followed by the JVM (libjvm.so).
30 * The JVM symbols may be translated by passing the output through c++filt.
31 *
32 * COPYRIGHT: Copyright (c) 2007 Brendan Gregg.
33 *
34 * CDDL HEADER START
35 *
36 *  The contents of this file are subject to the terms of the
37 *  Common Development and Distribution License, Version 1.0 only
38 *  (the "License").  You may not use this file except in compliance
39 *  with the License.
40 *
41 *  You can obtain a copy of the license at Docs/cddl1.txt
42 *  or http://www.opensolaris.org/os/licensing.
43 *  See the License for the specific language governing permissions
44 *  and limitations under the License.
45 *
46 * CDDL HEADER END
47 *
48 * 09-Sep-2007	Brendan Gregg	Created this.
49 */
50
51#pragma D option quiet
52#pragma D option jstackstrsize=1024
53
54/*
55 * Tunables
56 */
57#define DEPTH	10		/* stack depth, frames */
58#define RATE	101		/* sampling rate, Hertz */
59#define TOP	25		/* number of stacks to output */
60
61dtrace:::BEGIN
62{
63	printf("Sampling %d-level stacks at %d Hertz... Hit Ctrl-C to end.\n",
64	    DEPTH, RATE);
65}
66
67profile-RATE
68/pid == $target/
69{
70	@stacks[jstack(DEPTH)] = count();
71}
72
73dtrace:::END
74{
75	trunc(@stacks, TOP);
76	printf("Top %d most frequently sampled stacks,\n", TOP);
77	printa(@stacks);
78}
79