As @jjnoakes points out, you'll get malloc()==NULL if your ulimits are set. For a long-running program you definitely want to have a ulimit that will kick in b

As @jjnoakes points out, you'll get malloc()==NULL if your ulimits are set. For a long-running program you definitely want to have a ulimit that will kick in before the OOM killer does. Even in the absence of the OOM killer (i.e. the old days) you had to do this -- otherwise the machine might be swapping itself unresponsive for ages before you ever get malloc()==NULL