Help using Vtune for analyzing JAVA applications

[Rene_P_]

Hi All,

I am trying to use Intel VTUNE 2016 v2 for analyzing a simple java program using the general exploration mode. The Java program is as follows:-

public class SimpleEx {

public static void main(String[] args) {

for (int i = 0; i < 10; i++) {

System.out.println("Hello World");

}

}

}

I compile the above code as "javac -g SimpleEx". I use JDK v1.7

I have created a run.sh script which has one line"java SimpleEx"

I am using the GUI version by invoking ./amplxe-gui. Under the "Analysis Target tab", I select the application as run.sh. I select "Managed code profiling mode" as native and tick "analyze child processes". Then I select General Exploration analysis

After the analysis completes, none of the top-down or bottom-up stacks refer to the SimpleEx class or the main function. Most references look like "func@0x3c1222" etc.

What am I missing here? How to enable profiling of this java application? Appreciate any help in this regard.

Thanks

Rene

[Peter_W_Intel]

I don't know what is environment variable for Java_Home you specified, but what Java version to build then what Java version to run.

# ../jdk1.7.0_11/bin/javac -g SimpleEx.java

# amplxe-cl -c hotspots -- ../jdk1.7.0_11/bin/java SimpleEx

In order to capture more samples in output stream, you may increase iteration from "10" to "10000"

[root@prc-mic01 tmp]# amplxe-cl -R hotspots | more
amplxe: Using result path `/home/peter/tmp/r050hs'
amplxe: Executing actions 75 % Generating a report                             Function                                  CPU Time  CPU Time:Effective Time  CPU
 Time:Effective Time:Idle  CPU Time:Effective Time:Poor  CPU Time:Effective Time
:Ok  CPU Time:Effective Time:Ideal  CPU Time:Effective Time:Over  CPU Time:Spin
Time  CPU Time:Overhead Time  Module           Function (Full)                  
                                      Source File  Start Address
----------------------------------------  --------  -----------------------  ---
-------------------------  ----------------------------  -----------------------
---  -----------------------------  ----------------------------  --------------
----  ----------------------  ---------------  ---------------------------------
------------------------------------  -----------  --------------
Interpreter                                 0.070s                   0.070s     
                   0.010s                        0.060s                         
 0s                             0s                            0s                
  0s                      0s  [Dynamic code]   Interpreter                      
                                      [Unknown]    0x7fafb1005460
dlopen                                      0.060s                   0.060s     
                       0s                        0.060s                         
 0s                             0s                            0s                
  0s                      0s  libdl.so.2       dlopen                           
                                      [Unknown]    0x3943c00eb0  
Java_java_io_FileOutputStream_writeBytes    0.050s                   0.050s     
                       0s                        0.050s                         
 0s                             0s                            0s                                                         
  0s                      0s  libjava.so       Java_java_io_FileOutputStream_wri
teBytes                               [Unknown]    0xe820        
Matcher::xform                              0.020s                   0.020s     
                       0s                        0.020s                         
 0s                             0s                            0s                
  0s                      0s  libjvm.so        Matcher::xform(Node*, int)       
                                      [Unknown]    0x6b6750      

[Rene_P_]

Hi Peter,

Thanks a lot for your reply.

The hotpot analysis result does not have any reference to the main function (of the SimpleEx class). Is it being referred to by the "Dynamic code" section of the result.

Eventually, I would like to use VTUNE for analyzing java programs with larger (more) functions/classes and identify hotspot functions/modules, call stack information and perform the new general exploration analysis on the hot functions. How can I do the same i.e, see function/module names of the associated java program instances in the vtune analysis result?

Thanks again for your help.

Best Regards,

Rene

[Peter_W_Intel]

Your application ran shortly and there is no work in main() of class. See my example, attached.

# amplxe-cl -c general-exploration -knob enable-stack-collection=true -d 10 -- ../jdk1.7.0_11/bin/java test

Use amplxe-gui to open result "amplxe-gui r008ge", for example

[Rene_P_]

Hi Peter,

Thanks again for your reply.

I followed the instructions you provided.

1. downloaded the test.java file

2. Compiled using /usr/lib/jvm/java-7-openjdk-amd64/bin/javac -g test.java

3. Ran vtune general exploration using "amplxe-cl -c general-exploration -knob enable-stack-collection=true -d 10 -- /usr/lib/jvm/java-7-openjdk-amd64/bin/java test"

4. Using gui to analyze results :- amplxe-gui r000ge/

 I can see the main function in the call stack now (thanks for the tips), but the call-stack is still broken - the screenshot is attached herewith. It is different from the call stack that you posted before, I am not sure what I am missing here. Can you please help me identify the issue?501971501972

I am also attaching vtune amplxe-cl output here for your reference.

Thanks a lot for your help.

Best Regards,

Rene

[Rene_P_]

Hi,

I am not sure why vtune cannot resolve following dependencies:-

amplxe: Warning: Cannot locate debugging symbols for file `/opt/intel/vtune_amplifier_xe_2016.2.0.444464/lib64/runtime/libamplxe_samplingmrte_javaprof_1.0.so'.
amplxe: Warning: Cannot locate debugging symbols for file `/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/libjava.so'.
amplxe: Warning: Cannot locate debugging symbols for file `/lib/x86_64-linux-gnu/libz.so.1.2.8'.
amplxe: Executing actions 23 % Resolving information for `libjli.so'           
amplxe: Warning: Cannot locate debugging symbols for file `/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/jli/libjli.so'.
amplxe: Executing actions 23 % Resolving information for `libc-2.19.so'        
amplxe: Warning: Cannot locate file `vtsspp.ko'.
amplxe: Warning: Cannot locate file `/usr/lib/debug/lib/modules/3.19.0-49-generic/vmlinux'.
amplxe: Executing actions 24 % Resolving information for `[Dynamic code]'      
amplxe: Warning: Cannot locate debugging symbols for file `/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/server/libjvm.so'.
amplxe: Executing actions 24 % Resolving information for `libzip.so'           
amplxe: Warning: Cannot locate debugging symbols for file `/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/libzip.so'.
amplxe: Executing actions 24 % Resolving information for dangling locations    
amplxe: Warning: Cannot locate file `wl.ko'.
amplxe: Executing actions 28 % Resolving call target names for dynamic code    
amplxe: Warning: Cannot locate debugging symbols for file `/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/server/libjvm.so'.
amplxe: Executing actions 75 % Generating a report   

Can the broken call stack be because of this?

My JAVA version, java -version
java version "1.7.0_95"
OpenJDK Runtime Environment (IcedTea 2.6.4) (7u95-2.6.4-0ubuntu0.14.04.2)
OpenJDK 64-Bit Server VM (build 24.95-b01, mixed mode)

Thanks,

Rene

[Peter_W_Intel]

My grouping was "Function \ Call Stack", you used "Source Function / Function / Call Stack" grouping.

It should be:

Test::main

   Test:: main

        jni_CallStaticVoidMethod<-JavaMain<-start_thread

Other: their is no debug info for some modules when finalizing data, VTune will display function as [Function+offset] or [Module] format, please ignore them.

[Rene_P_]

Hi Peter,

Thanks for your reply.

I tried using the Function/call stack option as you suggested. But the call stack I get still looks broken, not same as what you had posted before (attached is a snapshot). I am not able to understand why the output is different/broken?

Thanks,

Rene

502022

[Peter_W_Intel · Accepted solution]

> I tried using the Function/call stack option as you suggested. But the call stack I get still looks broken,

probably you used java version from the system to build, but I used other.

# /home/peter/jdk1.7.0_11/bin/java -version
java version "1.7.0_11"
Java(TM) SE Runtime Environment (build 1.7.0_11-b21)
Java HotSpot(TM) 64-Bit Server VM (build 23.6-b04, mixed mode)

# java -version
java version "1.6.0_22"
OpenJDK Runtime Environment (IcedTea6 1.10.4) (rhel-1.41.1.10.4.el6-x86_64)
OpenJDK 64-Bit Server VM (build 20.0-b11, mixed mode)

[Rene_P_]

Hi Peter,

Yes, you are right. I downloaded the Java Hotspot v1.8 JDK. I compiled/ran the test program again with the hotspot JDK. Now the call stack includes some missing functions (callstack snapshot attached herewith).

Thanks a lot for your help.

Best Regards,

Rene

[Rene_P_]

502026

Forgot to attach before.

[Artyom_K_Intel1]

Vtune profiles Java methods which were JITed. It does not recognize methods which are interpreted by JVM (those which are not hot, usually main function).

See Java support limitations section in our docs - https://software.intel.com/en-us/node/544058#GUID-41CC895F-7E4F-47C6-8872-332C10E234A2