I think it is a good idea to clean the JVM arguments to something like:
when you want to optimize for response time: -Xms512m -Xmx512m -Xns256m -XXkeepAreaRatio:25 -Xgcprio:pausetime -XpauseTarget:200ms
or when you want to optimize for throughput: -Xms512m -Xmx512m -Xss128k -Xgcprio:throughput
The options Xms, Xms and Xns can be configured to your preference. Note however that when you are running on 32bit machine
that the maximum (Xmx) cannot be higher than 1750M. You must also account for the memory usage of the JVM itself (1250M to 1500M
is probably a good value on a 32bit system).
To check which linux version you are using you can use uname -a.