Jasper report cannot generate large report with subreport

[bbrena]

I need to generate a large report. I am able to compile and jrxml files and generate .jasper files but it gets stucks and doesnt generate the report in csv which i need. I am using a json file data source. the file is 11894 KB in size. I have to mention when i remore the subreport reference and just generate the first columns of the report with the same jsn it work. But once i incude the supreport to complete the fields i need, the program doesnt complete and gets stuck. I have let it run for hours to see if it will generate but just take a longer time but it didnt do anything after 8 hours of waiting. It gets stuck when it is filling the method. I an using the same methods in the jasper jsondatasource sample code.

I am using jasper 6.1.1