Custom Reports with PDF output heap issue

Issue : The following issue in custom report for pdf output


"Error occurred during initialization of VM
Could not reserve enough space for object heap
"



Solution :
change all concurrent requets options from  "-Xms1024M -Xmx1024M"   to "-Xms128M -Xmx512M"


Ref:

Configuring various JVM tuning parameters for Oracle E-Business suite 11i and R12 [ID 567551.1]
JVM: Guidelines to setup the Java Virtual Machine in Apps Ebusiness Suite 11i and R12 [ID 362851.1]