It depends on whether the system you're using overcommits memory. Some OSes (eg Linux) provide settings to limit virtual memory use to some percentage of physi

It depends on whether the system you're using overcommits memory. Some OSes (eg Linux) provide settings to limit virtual memory use to some percentage of physical memory. See http://engineering.pivotal.io/post/virtual_memory_settings_in_linux_-_the_problem_with_overcommit/ http://engineering.pivotal.io/post/virtual_memory_settings_i... The only time you should avoid checking malloc() return values are for special mallocs that really cannot return NULL. One example is FreeBSD's kernel malloc() when called with the M_WAITOK flag.