When i start the Jboss application server the percentage of heap used splashes 99% how you see follows:.

{Heap before GC invocations=142 (full 1):
PSYoungGen total 56832K, used 55472K [0xb07d0000, 0xb40b0000, 0xb40b0000)
eden space 55360K, 100% used [0xb07d0000,0xb3de0000,0xb3de0000)
from space 1472K, 7% used [0xb3f40000,0xb3f5c000,0xb40b0000)
to space 1408K, 0% used [0xb3de0000,0xb3de0000,0xb3f40000)
PSOldGen total 466048K, used 198091K [0x940b0000, 0xb07d0000, 0xb07d0000)
object space 466048K, 42% used [0x940b0000,0xa0222d38,0xb07d0000)
PSPermGen total 64384K, used 64371K [0x740b0000, 0x77f90000, 0x940b0000)
object space 64384K, 99% used [0x740b0000,0x77f8ce08,0x77f90000)
Heap after GC invocations=142 (full 1):
PSYoungGen total 56768K, used 144K [0xb07d0000, 0xb40b0000, 0xb40b0000)
eden space 55360K, 0% used [0xb07d0000,0xb07d0000,0xb3de0000)
from space 1408K, 10% used [0xb3de0000,0xb3e04000,0xb3f40000)
to space 1280K, 0% used [0xb3f70000,0xb3f70000,0xb40b0000)
PSOldGen total 466048K, used 198091K [0x940b0000, 0xb07d0000, 0xb07d0000)
object space 466048K, 42% used [0x940b0000,0xa0222d38,0xb07d0000)
PSPermGen total 64384K, used 64371K [0x740b0000, 0x77f90000, 0x940b0000)
object space 64384K, 99% used [0x740b0000,0x77f8ce08,0x77f90000)
}

I am starting jboss with the following jvm params; -Xms512m -Xmx512m -XX:MaxPermSize=512M -XX:+PrintHeapAtGC