Java memory usage with Xdebug option

[Vincenzo]

Anyone of you knows why executing a java program using
standard options and Xdebug option memory usage are different ?
For example, using this command to execute java (141):
java -Xmx${JAVA_MEM}m -Xms${JAVA_MEM}m -cp $CLASSPATH ${COMMAND}

I have this memory usage:
Date %CPU %MEM VSZ RSS
08/03/05 17:09 5.5 6.1 92.2M 31M
08/03/05 17:10 5.3 6.4 95.2M 33M
08/03/05 17:11 5.0 6.5 95.2M 33M
....

If I run the same code with Xdebug option:
java -cp $CLASSPATH -Xdebug -Djava.compiler=NONE ${COMMAND}

I have this memory usage:
Date %CPU %MEM VSZ RSS
08/04/05 11:17 0.0 2.9 19.1M 15M
08/04/05 11:18 0.0 2.9 19.1M 15M
08/04/05 11:19 0.0 2.9 19.1M 15M
08/04/05 11:20 0.0 2.9 19.1M 15M

Any idea ?

Thanks,
Vincenzo

 

[Raymond DeCampo]

Anyone of you knows why executing a java program using
standard options and Xdebug option memory usage are different ?
For example, using this command to execute java (141):
java -Xmx${JAVA_MEM}m -Xms${JAVA_MEM}m -cp $CLASSPATH ${COMMAND}

I have this memory usage:
Date %CPU %MEM VSZ RSS
08/03/05 17:09 5.5 6.1 92.2M 31M
08/03/05 17:10 5.3 6.4 95.2M 33M
08/03/05 17:11 5.0 6.5 95.2M 33M
...

If I run the same code with Xdebug option:
java -cp $CLASSPATH -Xdebug -Djava.compiler=NONE ${COMMAND}

I have this memory usage:
Date %CPU %MEM VSZ RSS
08/04/05 11:17 0.0 2.9 19.1M 15M
08/04/05 11:18 0.0 2.9 19.1M 15M
08/04/05 11:19 0.0 2.9 19.1M 15M
08/04/05 11:20 0.0 2.9 19.1M 15M

Any idea ?

Besides the obvious facts that
1) one of the commands specifies a minimum starting heap size, and
2) the JVM must occur some overhead when running in debug mode?

HTH,
Ray