GETRUSAGE(2) | System Calls Manual | GETRUSAGE(2) |
getrusage
— get
information about resource utilization
#include
<sys/resource.h>
int
getrusage
(int
who, struct rusage
*rusage);
getrusage
()
returns resource usage information for argument who,
which can be one of the following:
RUSAGE_SELF
RUSAGE_CHILDREN
RUSAGE_THREAD
The buffer to which rusage points will be filled in with the following structure:
struct rusage { struct timeval ru_utime; /* user time used */ struct timeval ru_stime; /* system time used */ long ru_maxrss; /* max resident set size */ long ru_ixrss; /* integral shared text 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 */ };
The fields are interpreted as follows:
The numbers ru_inblock and ru_oublock 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.
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.
getrusage
() will fail if:
The getrusage
() function conforms to
IEEE Std 1003.1-2008 (“POSIX.1”).
The RUSAGE_THREAD
flag is an extension to
that specification.
A predecessor to getrusage
(),
times
(), first appeared in
Version 3 AT&T UNIX. The
getrusage
() system call first appeared in
4.1cBSD.
The RUSAGE_THREAD
flag has been available
since OpenBSD 4.8.
There is no way to obtain information about a child process that has not yet terminated.
February 28, 2015 | OpenBSD-current |