I have a program which forks out child processes (a limit of 4 simultaneous processes is set due to server capacity). In total, there are about 12 processes to run and 2 of them require long processing time: 2-3 hours each. There was a time when the program hit the segmentation fault problem. I understand that when each process is forked, a stack is allocated for that process. My question: what is the usual size of the stack? Is this problem caused by the long processes? Currently, the program does not include signal handling.

Thanks for the answer!

I have another issue here. Is there a limit on the number of processes (by using "ps" to check) which can be launched by a user? For example, I have concurrent 4 child processes (a limit set by the C++ program) running along with other processes. There was a time when the parent could not fork new child processes when the existing ones completed. Is it true that once the number of processes (shown by using "ps" command) hits the limit, no new child process can be forked? How do I check/change this limit?