+++ /dev/null
-.\" Copyright (c) 1992 Drew Eckhardt, March 28, 1992
-.\" and Copyright (c) 2002 Michael Kerrisk
-.\"
-.\" %%%LICENSE_START(VERBATIM)
-.\" Permission is granted to make and distribute verbatim copies of this
-.\" manual provided the copyright notice and this permission notice are
-.\" preserved on all copies.
-.\"
-.\" Permission is granted to copy and distribute modified versions of this
-.\" manual under the conditions for verbatim copying, provided that the
-.\" entire resulting derived work is distributed under the terms of a
-.\" permission notice identical to this one.
-.\"
-.\" Since the Linux kernel and libraries are constantly changing, this
-.\" manual page may be incorrect or out-of-date. The author(s) assume no
-.\" responsibility for errors or omissions, or for damages resulting from
-.\" the use of the information contained herein. The author(s) may not
-.\" have taken the same level of care in the production of this manual,
-.\" which is licensed free of charge, as they might when working
-.\" professionally.
-.\"
-.\" Formatted or processed versions of this manual, if unaccompanied by
-.\" the source, must acknowledge the copyright and authors of this work.
-.\" %%%LICENSE_END
-.\"
-.\" 2004-11-16 -- mtk: the getrlimit.2 page, which formerly included
-.\" coverage of getrusage(2), has been split, so that the latter is
-.\" now covered in its own getrusage.2. For older details of change
-.\" history, etc., see getrlimit.2
-.\"
-.\" Modified 2004-11-16, mtk, Noted that the nonconformance
-.\" when SIGCHLD is being ignored is fixed in 2.6.9.
-.\" 2008-02-22, Sripathi Kodi <sripathik@in.ibm.com>: Document RUSAGE_THREAD
-.\" 2008-05-25, mtk, clarify RUSAGE_CHILDREN + other clean-ups.
-.\" 2010-05-24, Mark Hills <mark@pogo.org.uk>: Description of fields,
-.\" document ru_maxrss
-.\" 2010-05-24, mtk, enhanced description of various fields
-.\"
-.TH GETRUSAGE 2 2014-05-10 "Linux" "Linux Programmer's Manual"
-.SH NAME
-getrusage \- get resource usage
-.SH SYNOPSIS
-.B #include <sys/time.h>
-.br
-.B #include <sys/resource.h>
-.sp
-.BI "int getrusage(int " who ", struct rusage *" usage );
-.SH DESCRIPTION
-.PP
-.BR getrusage ()
-returns resource usage measures for
-.IR who ,
-which can be one of the following:
-.TP
-.B RUSAGE_SELF
-Return resource usage statistics for the calling process,
-which is the sum of resources used by all threads in the process.
-.TP
-.B RUSAGE_CHILDREN
-Return resource usage statistics for all children of the
-calling process that have terminated and been waited for.
-These statistics will include the resources used by grandchildren,
-and further removed descendants,
-if all of the intervening descendants waited on their terminated children.
-.TP
-.BR RUSAGE_THREAD " (since Linux 2.6.26)"
-Return resource usage statistics for the calling thread.
-The
-.B _GNU_SOURCE
-feature test macro must be defined (before including
-.I any
-header file)
-in order to obtain the definition of this constant from
-.IR <sys/resource.h> .
-.PP
-The resource usages are returned in the structure pointed to by
-.IR usage ,
-which has the following form:
-.PP
-.in +4n
-.nf
-struct rusage {
- struct timeval ru_utime; /* user CPU time used */
- struct timeval ru_stime; /* system CPU 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 (soft page faults) */
- long ru_majflt; /* page faults (hard page faults) */
- long ru_nswap; /* swaps */
- long ru_inblock; /* block input operations */
- long ru_oublock; /* block output operations */
- long ru_msgsnd; /* IPC messages sent */
- long ru_msgrcv; /* IPC messages received */
- long ru_nsignals; /* signals received */
- long ru_nvcsw; /* voluntary context switches */
- long ru_nivcsw; /* involuntary context switches */
-};
-.fi
-.in
-.PP
-Not all fields are completed;
-unmaintained fields are set to zero by the kernel.
-(The unmaintained fields are provided for compatibility with other systems,
-and because they may one day be supported on Linux.)
-The fields are interpreted as follows:
-.TP
-.I ru_utime
-This is the total amount of time spent executing in user mode,
-expressed in a
-.I timeval
-structure (seconds plus microseconds).
-.TP
-.I ru_stime
-This is the total amount of time spent executing in kernel mode,
-expressed in a
-.I timeval
-structure (seconds plus microseconds).
-.TP
-.IR ru_maxrss " (since Linux 2.6.32)"
-This is the maximum resident set size used (in kilobytes).
-For
-.BR RUSAGE_CHILDREN ,
-this is the resident set size of the largest child, not the maximum
-resident set size of the process tree.
-.TP
-.IR ru_ixrss " (unmaintained)"
-This field is currently unused on Linux.
-.\" On some systems,
-.\" this is the integral of the text segment memory consumption,
-.\" expressed in kilobyte-seconds.
-.TP
-.IR ru_idrss " (unmaintained)"
-This field is currently unused on Linux.
-.\" On some systems, this is the integral of the data segment memory consumption,
-.\" expressed in kilobyte-seconds.
-.TP
-.IR ru_isrss " (unmaintained)"
-This field is currently unused on Linux.
-.\" On some systems, this is the integral of the stack memory consumption,
-.\" expressed in kilobyte-seconds.
-.TP
-.I 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
-.I ru_majflt
-The number of page faults serviced that required I/O activity.
-.TP
-.IR ru_nswap " (unmaintained)"
-This field is currently unused on Linux.
-.\" On some systems, this is the number of swaps out of physical memory.
-.TP
-.IR ru_inblock " (since Linux 2.6.22)"
-The number of times the filesystem had to perform input.
-.TP
-.IR ru_oublock " (since Linux 2.6.22)"
-The number of times the filesystem had to perform output.
-.TP
-.IR ru_msgsnd " (unmaintained)"
-This field is currently unused on Linux.
-.\" On FreeBSD 6.2, this appears to measure messages sent over sockets
-.\" On some systems,
-.\" this field records the number of messages sent over sockets.
-.TP
-.IR ru_msgrcv " (unmaintained)"
-This field is currently unused on Linux.
-.\" On FreeBSD 6.2, this appears to measure messages received over sockets
-.\" On some systems,
-.\" this field records the number of messages received over sockets.
-.TP
-.IR ru_nsignals " (unmaintained)"
-This field is currently unused on Linux.
-.\" On some systems, this field records the number of signals received.
-.TP
-.IR ru_nvcsw " (since Linux 2.6)"
-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).
-.TP
-.IR ru_nivcsw " (since Linux 2.6)"
-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.
-.PP
-.SH RETURN VALUE
-On success, zero is returned.
-On error, \-1 is returned, and
-.I errno
-is set appropriately.
-.SH ERRORS
-.TP
-.B EFAULT
-.I usage
-points outside the accessible address space.
-.TP
-.B EINVAL
-.I who
-is invalid.
-.SH CONFORMING TO
-SVr4, 4.3BSD.
-POSIX.1-2001 specifies
-.BR getrusage (),
-but specifies only the fields
-.I ru_utime
-and
-.IR ru_stime .
-
-.B RUSAGE_THREAD
-is Linux-specific.
-.SH NOTES
-Resource usage metrics are preserved across an
-.BR execve (2).
-
-Including
-.I <sys/time.h>
-is not required these days, but increases portability.
-(Indeed,
-.I struct timeval
-is defined in
-.IR <sys/time.h> .)
-.PP
-In Linux kernel versions before 2.6.9, if the disposition of
-.B SIGCHLD
-is set to
-.B SIG_IGN
-then the resource usages of child processes
-are automatically included in the value returned by
-.BR RUSAGE_CHILDREN ,
-although POSIX.1-2001 explicitly prohibits this.
-This nonconformance is rectified in Linux 2.6.9 and later.
-.\" See the description of getrusage() in XSH.
-.\" A similar statement was also in SUSv2.
-.LP
-The structure definition shown at the start of this page
-was taken from 4.3BSD Reno.
-
-Ancient systems provided a
-.BR vtimes ()
-function with a similar purpose to
-.BR getrusage ().
-For backward compatibility, glibc also provides
-.BR vtimes ().
-All new applications should be written using
-.BR getrusage ().
-
-See also the description of
-.IR /proc/PID/stat
-in
-.BR proc (5).
-.SH SEE ALSO
-.BR clock_gettime (2),
-.BR getrlimit (2),
-.BR times (2),
-.BR wait (2),
-.BR wait4 (2),
-.BR clock (3)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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