The debugger consists of two parts (main and kernel), to accommodate the debugging of multiprocess programs. o For a program that runs in one process, a debugging session requires two processes instead of one. o For a multiprocess program, a debugging session requires as many processes as are used by the program, plus an additional process for the main debugger. Under these conditions, several users who are simultaneously debugging programs can place an additional load on a system. The subtopics describe the resources used by the debugger so that you can tune your system for this activity. The discussion covers only the resources used by the debugger. In the case of multiprocess programs, you might also have to tune your system to support the programs themselves.
1 – User Quotas
Each user needs a PRCLM quota sufficient to create an additional process for the debugger, beyond the number of processes needed by the program. BYTLM, ENQLM, FILLM, and PGFLQUOTA are pooled quotas. They may need to be increased to account for the debugger process as follows: o Each user's ENQLM quota should be increased by at least the number of processes being debugged. o Each user's PGFLQUOTA might need to be increased. If a user has an insufficient PGFLQUOTA, the debugger might fail to activate or might cause "virtual memory exceeded" errors during execution. o Each user's BYTLM and FILLM quotas may need to be increased. The debugger requires BYTLM and FILLM quotas sufficient to open each image file being debugged, the corresponding source files, and the debugger input, output, and log files.
2 – System Resources
The kernel and main debugger communicate through global sections. The main debugger communicates with up to 8 kernel debuggers through a 65-page global section. Therefore, the system global- page and global-section parameters (GBLPAGES and GBLSECTIONS, respectively) might need to be increased. For example, if 10 users are using the debugger simultaneously, 10 global sections using a total of 650 global pages are required by the debugger.