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j_profile.d revision 1.1 
      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,v 1.1 2015/09/30 22:01:09 christos Exp $
      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 
     61 dtrace:::BEGIN
     62 {
     63 	printf("Sampling %d-level stacks at %d Hertz... Hit Ctrl-C to end.\n",
     64 	    DEPTH, RATE);
     65 }
     66 
     67 profile-RATE
     68 /pid == $target/
     69 {
     70 	@stacks[jstack(DEPTH)] = count();
     71 }
     72 
     73 dtrace:::END
     74 {
     75 	trunc(@stacks, TOP);
     76 	printf("Top %d most frequently sampled stacks,\n", TOP);
     77 	printa(@stacks);
     78 }
     79