Linux 4k resolution, create multiple openglwidget, will be killed by the system

In embedded Linux 4k resolution, I wrote a very simple example, just create multiple qopenglwidget simple, and then the system will kill the program started. . . If it is a widget or create a few qopenglwidget (about 3 or so), then the problem does not exist. After being killed off, I use the dmesg command to view the log, showing "" Out of memory: Kill process .... ". Very confused Why do they take up too much memory? At first I thought it was qopenglwidget usage errors, so I Try to run the same program on Windows pc (memory 16G), the result is no problem.