[apple/xnu.git] / bsd / man / man2 / getrusage.2

.\"	$NetBSD: getrusage.2,v 1.4 1995/02/27 12:33:23 cgd Exp $
.\"
.\" Copyright (c) 1985, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)getrusage.2	8.1 (Berkeley) 6/4/93
.\"
.Dd June 4, 1993
.Dt GETRUSAGE 2
.Os BSD 4
.Sh NAME
.Nm getrusage
.Nd get information about resource utilization
.Sh SYNOPSIS
.Fd #include <sys/time.h>
.Fd #include <sys/resource.h>
.Fd #define	RUSAGE_SELF	 0
.Fd #define	RUSAGE_CHILDREN	-1
.Ft int
.Fn getrusage "int who" "struct rusage *rusage"
.Sh DESCRIPTION
.Fn Getrusage
returns information describing the resources utilized by the current
process, or all its terminated child processes.
The
.Fa who
parameter is either
.Dv RUSAGE_SELF
or
.Dv RUSAGE_CHILDREN .
The buffer to which
.Fa rusage
points will be filled in with
the following structure:
.Bd -literal
struct rusage {
        struct timeval ru_utime; /* user time used */
        struct timeval ru_stime; /* system time used */
        long ru_maxrss;          /* integral 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 */
};
.Ed
.Pp
The fields are interpreted as follows:
.Bl -tag -width ru_minfltaa
.It Fa ru_utime
the total amount of time spent executing in user mode.
.It Fa ru_stime
the total amount of time spent in the system executing on behalf
of the process(es).
.It Fa ru_maxrss
the maximum resident set size utilized (in kilobytes).
.It Fa ru_ixrss
an \*(lqintegral\*(rq value indicating the amount of memory used
by the text segment
that was also shared among other processes.  This value is expressed
in units of kilobytes * ticks-of-execution.
.It Fa ru_idrss
an integral value of the amount of unshared memory residing in the
data segment of a process (expressed in units of
kilobytes * ticks-of-execution).
.It Fa ru_isrss
an integral value of the amount of unshared memory residing in the
stack segment of a process (expressed in units of
kilobytes * ticks-of-execution).
.It Fa 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.
.It Fa ru_majflt
the number of page faults serviced that required I/O activity.
.It Fa ru_nswap
the number of times a process was \*(lqswapped\*(rq out of main
memory.
.It Fa ru_inblock
the number of times the file system had to perform input.
.It Fa ru_oublock
the number of times the file system had to perform output.
.It Fa ru_msgsnd
the number of IPC messages sent.
.It Fa ru_msgrcv
the number of IPC messages received.
.It Fa ru_nsignals
the number of signals delivered.
.It Fa 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 availability of a resource).
.It Fa 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.
.El
.Sh NOTES
The numbers 
.Fa ru_inblock
and 
.Fa 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.
.Sh ERRORS
.Fn Getrusage
returns -1 on error.
The possible errors are:
.Bl -tag -width Er
.It Bq Er EINVAL
The
.Fa who
parameter is not a valid value.
.It Bq Er EFAULT
The address specified by the
.Fa rusage
parameter is not in a valid part of the process address space.
.El
.Sh SEE ALSO
.Xr gettimeofday 2 ,
.Xr wait 2
.Sh BUGS
There is no way to obtain information about a child process
that has not yet terminated.
.Sh HISTORY
The
.Fn getrusage
function call appeared in
.Bx 4.2 .
Commit	Line	Data
9bccf70c A	1	.\" $NetBSD: getrusage.2,v 1.4 1995/02/27 12:33:23 cgd Exp $
	2	.\"
	3	.\" Copyright (c) 1985, 1991, 1993
	4	.\" The Regents of the University of California. All rights reserved.
	5	.\"
	6	.\" Redistribution and use in source and binary forms, with or without
	7	.\" modification, are permitted provided that the following conditions
	8	.\" are met:
	9	.\" 1. Redistributions of source code must retain the above copyright
	10	.\" notice, this list of conditions and the following disclaimer.
	11	.\" 2. Redistributions in binary form must reproduce the above copyright
	12	.\" notice, this list of conditions and the following disclaimer in the
	13	.\" documentation and/or other materials provided with the distribution.
	14	.\" 3. All advertising materials mentioning features or use of this software
	15	.\" must display the following acknowledgement:
	16	.\" This product includes software developed by the University of
	17	.\" California, Berkeley and its contributors.
	18	.\" 4. Neither the name of the University nor the names of its contributors
	19	.\" may be used to endorse or promote products derived from this software
	20	.\" without specific prior written permission.
	21	.\"
	22	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	23	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	24	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	25	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	26	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	27	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	28	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	29	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	30	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	31	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	32	.\" SUCH DAMAGE.
	33	.\"
	34	.\" @(#)getrusage.2 8.1 (Berkeley) 6/4/93
	35	.\"
	36	.Dd June 4, 1993
	37	.Dt GETRUSAGE 2
	38	.Os BSD 4
	39	.Sh NAME
	40	.Nm getrusage
	41	.Nd get information about resource utilization
	42	.Sh SYNOPSIS
	43	.Fd #include <sys/time.h>
	44	.Fd #include <sys/resource.h>
	45	.Fd #define RUSAGE_SELF 0
	46	.Fd #define RUSAGE_CHILDREN -1
	47	.Ft int
	48	.Fn getrusage "int who" "struct rusage *rusage"
	49	.Sh DESCRIPTION
	50	.Fn Getrusage
	51	returns information describing the resources utilized by the current
	52	process, or all its terminated child processes.
	53	The
	54	.Fa who
	55	parameter is either
	56	.Dv RUSAGE_SELF
	57	or
	58	.Dv RUSAGE_CHILDREN .
	59	The buffer to which
	60	.Fa rusage
	61	points will be filled in with
	62	the following structure:
	63	.Bd -literal
	64	struct rusage {
65	struct timeval ru_utime; /* user time used */
66	struct timeval ru_stime; /* system time used */
67	long ru_maxrss; /* integral max resident set size */
68	long ru_ixrss; /* integral shared text memory size */
69	long ru_idrss; /* integral unshared data size */
70	long ru_isrss; /* integral unshared stack size */
71	long ru_minflt; /* page reclaims */
72	long ru_majflt; /* page faults */
73	long ru_nswap; /* swaps */
74	long ru_inblock; /* block input operations */
75	long ru_oublock; /* block output operations */
76	long ru_msgsnd; /* messages sent */
77	long ru_msgrcv; /* messages received */
78	long ru_nsignals; /* signals received */
79	long ru_nvcsw; /* voluntary context switches */
80	long ru_nivcsw; /* involuntary context switches */
81	};
82	.Ed
83	.Pp
84	The fields are interpreted as follows:
85	.Bl -tag -width ru_minfltaa
86	.It Fa ru_utime
87	the total amount of time spent executing in user mode.
88	.It Fa ru_stime
89	the total amount of time spent in the system executing on behalf
90	of the process(es).
91	.It Fa ru_maxrss
92	the maximum resident set size utilized (in kilobytes).
93	.It Fa ru_ixrss
94	an \(lqintegral\(rq value indicating the amount of memory used
95	by the text segment
96	that was also shared among other processes. This value is expressed
97	in units of kilobytes * ticks-of-execution.
98	.It Fa ru_idrss
99	an integral value of the amount of unshared memory residing in the
100	data segment of a process (expressed in units of
101	kilobytes * ticks-of-execution).
102	.It Fa ru_isrss
103	an integral value of the amount of unshared memory residing in the
104	stack segment of a process (expressed in units of
105	kilobytes * ticks-of-execution).
106	.It Fa ru_minflt
107	the number of page faults serviced without any I/O activity; here
108	I/O activity is avoided by \(lqreclaiming\(rq a page frame from
109	the list of pages awaiting reallocation.
110	.It Fa ru_majflt
111	the number of page faults serviced that required I/O activity.
112	.It Fa ru_nswap
113	the number of times a process was \(lqswapped\(rq out of main
114	memory.
115	.It Fa ru_inblock
116	the number of times the file system had to perform input.
117	.It Fa ru_oublock
118	the number of times the file system had to perform output.
119	.It Fa ru_msgsnd
120	the number of IPC messages sent.
121	.It Fa ru_msgrcv
122	the number of IPC messages received.
123	.It Fa ru_nsignals
124	the number of signals delivered.
125	.It Fa ru_nvcsw
126	the number of times a context switch resulted due to a process
127	voluntarily giving up the processor before its time slice was
128	completed (usually to await availability of a resource).
129	.It Fa ru_nivcsw
130	the number of times a context switch resulted due to a higher
131	priority process becoming runnable or because the current process
132	exceeded its time slice.
133	.El
134	.Sh NOTES
135	The numbers
136	.Fa ru_inblock
137	and
138	.Fa ru_oublock
139	account only for real
140	I/O; data supplied by the caching mechanism is charged only
141	to the first process to read or write the data.
142	.Sh ERRORS
143	.Fn Getrusage
144	returns -1 on error.
145	The possible errors are:
146	.Bl -tag -width Er
147	.It Bq Er EINVAL
148	The
149	.Fa who
150	parameter is not a valid value.
151	.It Bq Er EFAULT
152	The address specified by the
153	.Fa rusage
154	parameter is not in a valid part of the process address space.
155	.El
156	.Sh SEE ALSO
157	.Xr gettimeofday 2 ,
158	.Xr wait 2
159	.Sh BUGS
160	There is no way to obtain information about a child process
161	that has not yet terminated.
162	.Sh HISTORY
163	The
164	.Fn getrusage
165	function call appeared in
166	.Bx 4.2 .