Java Memory Profiler

JMP - Java Memory Profiler

General
About
Installation
Licence
Changelog
Screenshot
Performance

Documentation
users_guide [ps]
users_guide [pdf]
users_guide [lyx]

Download
Source
Current version: 0.51.1
jmp.tar.gz

Other versions jmp-0.51.1.tar.gz
jmp-0.50.2.tar.gz
jmp/0.18, gtk/1.2
jmp-0.18.tar.gz

Binaries
jmp.deb [0.48, i386]
jmp.deb [0.42, amd64]
jmp.deb [0.48, ppc]
jmp.dll [0.50.1]
gtk+/2.2.0 Win32

Old versions

Contacts
Robert Olofsson
robo@khelekore.org

Performance

Depending on how you run jmp it takes between 1.5 and 20 times as long for the java program to complete. JVMPI is quite slow, enabling all events that jmp uses can make the program take up to 10 times as long.

There is a big difference between the available jvms, for example the IBM jvm has previously done a lot more inlining even when jvmpi was enabled causing it to be much faster for profiling.

The tests done here are artificial. You do not want to run with full profiling from the start. You do want to run with minimal profiling and when you have reached an interesting state turn on object tracing or method tracing.

Note that the testing done here is only an indication on how fast (or slow) jmp is, your milage may vary.

The standard test case for jmp is running the RabbIT proxy on localhost. And then time a wget for 31 standard url (jmp website) from the local webserver, like this:

robo@orc:~/src/RabbIT2 > java -Xrunjmp rabbit.proxy.Proxy & robo@orc:~/slask/hubba > export http_proxy=http://orc:9666/ robo@orc:~/slask/hubba > time wget -o ../logfile -i ../urls real 0m1.804s user 0m0.021s sys 0m0.071s

Timing table for this test under jmp/0.41 and RabbIT/2.0.29. Test machine is an AMD athlon 2.8 GHz. 512 MB RAM using Linux/2.6.4. Running debian/GNU linux unstable branch. The webserver is a standard apache/2.0.48

SUN 1.4.2_03 SUN 1.5.0-beta1

Not using a proxy - 0.149 0.149

Without JMP java rabbit.proxy.Proxy 1.410 1.431

JMP tracing objects java -Xrunjmp:nomethods,nogui rabbit.proxy.Proxy 1.717 1.804

Hacked JMP to time JVMPI overhead. Method tracing, immediate return. java -Xrunjmp:noobjects,nogui rabbit.proxy.Proxy 2.899 2.203

JMP tracing methods java -Xrunjmp:noobjects,nogui rabbit.proxy.Proxy 4.055 3.341

JMP tracing objects and methods, not showing gui java -Xrunjmp:nogui rabbit.proxy.Proxy 4.469 3.527

JMP tracing objects and methods showing gui java -Xrunjmp rabbit.proxy.Proxy 4.837 4.044

The test performes a number of operations:

SUN 1.4.2_03 SUN 1.5.0-beta1

c_class_load 612 736

c_class_unload 3 3

c_object_alloc 72 318 69 040

c_object_move 8 79 20 994

c_object_free 42 503 54 247

c_thread_start 28 27

c_thread_end 15 15

c_method_entry 884 527 964 883

c_method_exit 884 496 964 853

Old results
Testing on jmp/0.14 and rabbit/2.0.16 can be found