.TH GETRUSAGE 2 .SH NAME getrusage \- get information about resource utilization .SH SYNOPSIS .nf .ft B #include <resource.h> .PP .ft B getrusage(who, rusage) int who; struct rusage *rusage; .fi .SH DESCRIPTION .I Getrusage returns information describing the resources utilitized by the current process, or all its terminated child process. If the .I who parameter is RUSAGE_SELF (0), the usage values are for only the calling process. If .I who is RUSAGE_CHILDREN (\-1), the values returned are for all child processes which have terminated. If .I rusage is non-zero, the buffer it points to will be filled in with the following structure: .PP .nf .RS .DT struct rusage { struct timeval ru_utime; /* user time used */ struct timeval ru_stime; /* system time used */ int ru_maxrss; int ru_ixrss; /* integral shared memory size */ int ru_idrss; /* integral unshared data " */ int ru_isrss; /* integral unshared stack " */ int ru_minflt; /* page reclaims */ int ru_majflt; /* page faults */ int ru_nswap; /* swaps */ int ru_inblock; /* block input operations */ int ru_oublock; /* block output operations */ int ru_msgsnd; /* messages sent */ int ru_msgrcv; /* messages received */ int ru_nsignals; /* signals received */ int ru_nvcsw; /* voluntary context switches */ int ru_nivcsw; /* involuntary context switches */ }; .RE .fi .PP The fields are interpreted as follows: .TP 15 ru_utime the total amount of time spent executing in user mode. .TP 15 ru_stime the total amount of time spent in the system executing on behalf of the process(es). .TP 15 ru_maxrss the maximum resident set size utilized (in kilobytes). .TP 15 ru_ixrss an \*(lqintegral\*(rq value indicating the amount of memory used which was also shared among other processes. This value is expressed in units of kilobytes * seconds-of-execution and is calculated by summing the number of shared memory pages in use each time the internal system clock ticks and then averaging over 1 second intervals. .TP 15 ru_idrss an integral value of the amount of unshared memory residing in the data segment of a process (expressed in units of kilobytes * seconds-of-execution). .TP 15 ru_isrss an integral value of the amount of unshared memory residing in the stack segment of a process (expressed in units of kilobytes * seconds-of-execution). .TP 15 ru_minflt the number of page faults serviced without any i/o activity; here i/o activity is avoided by \*(lqreclaiming\*(rq a page frame from the list of pages awaiting reallocation. .TP 15 ru_majflt the number of page faults serviced which required i/o activity. .TP 15 ru_nswap the number of times a process was \*(lqswapped\*(rq out of main memory. .TP 15 ru_inblock the number of times the file system had to perform input. .TP 15 ru_outblock the number of times the file system had to perform output. .TP 15 ru_msgsnd the number of ipc message sent. .TP 15 ru_msgrcv the number of ipc message received. .TP 15 ru_nsignals the number of signals delivered. .TP 15 ru_nvcsw the number of times a context switch resulted due to a process voluntarily giving up the processor before its time slice was completed (usually to await availabilty of a resource). .TP 15 ru_nivcsw the number of times a context switch resulted due to a higher priority process becoming runnable or because the current process exceeded its time slice. .SH NOTES The numbers .I ru_inblock and .I ru_outblock account only for real i/o; data supplied by the caching mechanism is charged only to the first process to read or write the data. .SH SEE ALSO gettimeofday(2), wait(2) .SH BUGS There is no way to obtain information about a child process which has not yet terminated.