Help: Master systemshell

Help: systemshell master-Linux general technology-Linux programming and kernel information, the following is a detailed reading. Recently, I encountered a problem where one of my linux processes (which is very large and occupies 70% of the machine's memory) is running a shell command, at first, the system ("shell command") is called, but the system will fork a sub-process to complete this operation, but the memory is insufficient (not enough to copy a new sub-process ), I would like to ask you what you can do and what you can do.