Process Limits

A process can be limited in its resource use
getrlimit(2), getrusage(2) to query the system
setrlimit(2) to change the limits
the shell offers "ulimit" as internal command

           struct rusage {
                 struct timeval ru_utime;   /* user time used */
                 struct timeval ru_stime;   /* system time used */
                 long ru_maxrss;            /* maximum resident set size */
                 long ru_ixrss; /* integral shared memory size */
                 long ru_idrss; /* integral unshared data size */
                 long ru_isrss; /* integral unshared stack size */
                 long ru_minflt;            /* page reclaims */
                 long ru_majflt;            /* page faults */
                 long ru_nswap;             /* swaps */
                 long ru_inblock;           /* block input operations */
                 long ru_oublock;           /* block output operations */
                 long ru_msgsnd;            /* messages sent */
                 long ru_msgrcv;            /* messages received */
                 long ru_nsignals;          /* signals received */
                 long ru_nvcsw;             /* voluntary context switches */
                 long ru_nivcsw;            /* involuntary context switches */
            };