3 GiBs of virtual space can get exhausted pretty quick, particularly when working with large files or a lot of mmaps fragmenting the virtual space. Just because

3 GiBs of virtual space can get exhausted pretty quick, particularly when working with large files or a lot of mmaps fragmenting the virtual space. Just because a process doesn't need more than 3 GiBs of physical RAM doesn't mean it's happy with only having 3 GiBs of virtual address space.