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1 | .\" Hey Emacs! This file is -*- nroff -*- source. |
2 | .\" | |
3 | .\" Copyright (c) 1992 Drew Eckhardt, March 28, 1992 | |
6883b3e7 | 4 | .\" and Copyright (c) 2002 Michael Kerrisk |
e3a887db MK |
5 | .\" |
6 | .\" Permission is granted to make and distribute verbatim copies of this | |
7 | .\" manual provided the copyright notice and this permission notice are | |
8 | .\" preserved on all copies. | |
9 | .\" | |
10 | .\" Permission is granted to copy and distribute modified versions of this | |
11 | .\" manual under the conditions for verbatim copying, provided that the | |
12 | .\" entire resulting derived work is distributed under the terms of a | |
13 | .\" permission notice identical to this one. | |
c13182ef | 14 | .\" |
e3a887db MK |
15 | .\" Since the Linux kernel and libraries are constantly changing, this |
16 | .\" manual page may be incorrect or out-of-date. The author(s) assume no | |
17 | .\" responsibility for errors or omissions, or for damages resulting from | |
18 | .\" the use of the information contained herein. The author(s) may not | |
19 | .\" have taken the same level of care in the production of this manual, | |
20 | .\" which is licensed free of charge, as they might when working | |
21 | .\" professionally. | |
c13182ef | 22 | .\" |
e3a887db MK |
23 | .\" Formatted or processed versions of this manual, if unaccompanied by |
24 | .\" the source, must acknowledge the copyright and authors of this work. | |
25 | .\" | |
c13182ef MK |
26 | .\" 2004-11-16 -- mtk: the getrlimit.2 page, which formerly included |
27 | .\" coverage of getrusage(2), has been split, so that the latter is | |
28 | .\" now covered in its own getrusage.2. For older details of change | |
0967c11f | 29 | .\" history, etc., see getrlimit.2 |
e3a887db | 30 | .\" |
cfea5132 | 31 | .\" Modified 2004-11-16, mtk, Noted that the nonconformance |
e3a887db | 32 | .\" when SIGCHLD is being ignored is fixed in 2.6.9. |
94ce95ef MK |
33 | .\" 2008-02-22, Sripathi Kodi <sripathik@in.ibm.com>: Document RUSAGE_THREAD |
34 | .\" 2008-05-25, mtk, clarify RUSAGE_CHILDREN + other clean-ups. | |
e3f4bf3e MK |
35 | .\" 2010-05-24, Mark Hills <mark@pogo.org.uk>: Description of fields, |
36 | .\" document ru_maxrss | |
57440a98 | 37 | .\" 2010-05-24, mtk, enhanced description of various fields |
e3a887db | 38 | .\" |
14f1e036 | 39 | .TH GETRUSAGE 2 2010-06-14 "Linux" "Linux Programmer's Manual" |
e3a887db MK |
40 | .SH NAME |
41 | getrusage \- get resource usage | |
42 | .SH SYNOPSIS | |
43 | .B #include <sys/time.h> | |
44 | .br | |
45 | .B #include <sys/resource.h> | |
46 | .sp | |
47 | .BI "int getrusage(int " who ", struct rusage *" usage ); | |
48 | .SH DESCRIPTION | |
49 | .PP | |
50 | .BR getrusage () | |
94ce95ef MK |
51 | returns resource usage measures for |
52 | .IR who , | |
53 | which can be one of the following: | |
54 | .TP | |
2914a14d MK |
55 | .B RUSAGE_SELF |
56 | Return resource usage statistics for the calling process, | |
94ce95ef MK |
57 | which is the sum of resources used by all threads in the process. |
58 | .TP | |
2914a14d | 59 | .B RUSAGE_CHILDREN |
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60 | Return resource usage statistics for all children of the |
61 | calling process that have terminated and been waited for. | |
62 | These statistics will include the resources used by grandchildren, | |
63 | and further removed descendants, | |
64 | if all of the intervening descendants waited on their terminated children. | |
65 | .TP | |
66 | .BR RUSAGE_THREAD " (since Linux 2.6.26)" | |
67 | Return resource usage statistics for the calling thread. | |
68 | .PP | |
69 | The resource usages are returned in the structure pointed to by | |
70 | .IR usage , | |
71 | which has the following form: | |
c13182ef | 72 | .PP |
a08ea57c | 73 | .in +4n |
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74 | .nf |
75 | struct rusage { | |
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76 | struct timeval ru_utime; /* user CPU time used */ |
77 | struct timeval ru_stime; /* system CPU time used */ | |
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78 | long ru_maxrss; /* maximum resident set size */ |
79 | long ru_ixrss; /* integral shared memory size */ | |
80 | long ru_idrss; /* integral unshared data size */ | |
81 | long ru_isrss; /* integral unshared stack size */ | |
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82 | long ru_minflt; /* page reclaims (soft page faults) */ |
83 | long ru_majflt; /* page faults (hard page faults) */ | |
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84 | long ru_nswap; /* swaps */ |
85 | long ru_inblock; /* block input operations */ | |
86 | long ru_oublock; /* block output operations */ | |
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87 | long ru_msgsnd; /* IPC messages sent */ |
88 | long ru_msgrcv; /* IPC messages received */ | |
e3a887db MK |
89 | long ru_nsignals; /* signals received */ |
90 | long ru_nvcsw; /* voluntary context switches */ | |
91 | long ru_nivcsw; /* involuntary context switches */ | |
92 | }; | |
93 | .fi | |
a08ea57c | 94 | .in |
d1cd1e05 | 95 | .PP |
14f1e036 MK |
96 | Not all fields are completed; |
97 | unmaintained fields are set to zero by the kernel. | |
98 | (The unmaintained fields are provided for compatibility with other systems, | |
99 | and because they may one day be supported on Linux.) | |
100 | The fields are interpreted as follows: | |
d1cd1e05 MH |
101 | .TP |
102 | .I ru_utime | |
57440a98 MK |
103 | This is the total amount of time spent executing in user mode, |
104 | expressed in a | |
105 | .I timeval | |
106 | structure (seconds plus microseconds). | |
d1cd1e05 MH |
107 | .TP |
108 | .I ru_stime | |
57440a98 MK |
109 | This is the total amount of time spent executing in kernel mode, |
110 | expressed in a | |
111 | .I timeval | |
112 | structure (seconds plus microseconds). | |
d1cd1e05 | 113 | .TP |
c90ccb4e | 114 | .IR ru_maxrss " (since Linux 2.6.32)" |
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115 | This is the maximum resident set size used (in kilobytes). For |
116 | .BR RUSAGE_CHILDREN , | |
c90ccb4e MH |
117 | this is the resident set size of the largest child, not the maximum |
118 | resident set size of the process tree. | |
d1cd1e05 MH |
119 | .TP |
120 | .IR ru_ixrss " (unmaintained)" | |
14f1e036 MK |
121 | This field is currently unused on Linux. |
122 | .\" On some systems, | |
123 | .\" this is the integral of the text segment memory consumption, | |
124 | .\" expressed in kilobyte-seconds. | |
d1cd1e05 MH |
125 | .TP |
126 | .IR ru_idrss " (unmaintained)" | |
14f1e036 MK |
127 | This field is currently unused on Linux. |
128 | .\" On some systems, this is the integral of the data segment memory consumption, | |
129 | .\" expressed in kilobyte-seconds. | |
d1cd1e05 MH |
130 | .TP |
131 | .IR ru_isrss " (unmaintained)" | |
14f1e036 MK |
132 | This field is currently unused on Linux. |
133 | .\" On some systems, this is the integral of the stack memory consumption, | |
134 | .\" expressed in kilobyte-seconds. | |
d1cd1e05 MH |
135 | .TP |
136 | .I ru_minflt | |
57440a98 | 137 | The number of page faults serviced without any I/O activity; here |
d1cd1e05 MH |
138 | I/O activity is avoided by \*(lqreclaiming\*(rq a page frame from |
139 | the list of pages awaiting reallocation. | |
140 | .TP | |
141 | .I ru_majflt | |
57440a98 | 142 | The number of page faults serviced that required I/O activity. |
d1cd1e05 MH |
143 | .TP |
144 | .IR ru_nswap " (unmaintained)" | |
14f1e036 MK |
145 | This field is currently unused on Linux. |
146 | .\" On some systems, this is the number of swaps out of physical memory. | |
d1cd1e05 MH |
147 | .TP |
148 | .IR ru_inblock " (since Linux 2.6.22)" | |
57440a98 | 149 | The number of times the file system had to perform input. |
d1cd1e05 MH |
150 | .TP |
151 | .IR ru_oublock " (since Linux 2.6.22)" | |
57440a98 | 152 | The number of times the file system had to perform output. |
d1cd1e05 MH |
153 | .TP |
154 | .IR ru_msgsnd " (unmaintained)" | |
14f1e036 | 155 | This field is currently unused on Linux. |
87f8e275 | 156 | .\" On FreeBSD 6.2, this appears to measure messages sent over sockets |
14f1e036 MK |
157 | .\" On some systems, |
158 | .\" this field records the number of messages sent over sockets. | |
d1cd1e05 MH |
159 | .TP |
160 | .IR ru_msgrcv " (unmaintained)" | |
14f1e036 | 161 | This field is currently unused on Linux. |
87f8e275 | 162 | .\" On FreeBSD 6.2, this appears to measure messages received over sockets |
14f1e036 MK |
163 | .\" On some systems, |
164 | .\" this field records the number of messages received over sockets. | |
d1cd1e05 MH |
165 | .TP |
166 | .IR ru_nsignals " (unmaintained)" | |
14f1e036 MK |
167 | This field is currently unused on Linux. |
168 | .\" On some systems, this field records the number of signals received. | |
d1cd1e05 MH |
169 | .TP |
170 | .IR ru_nvcsw " (since Linux 2.6)" | |
57440a98 | 171 | The number of times a context switch resulted due to a process |
d1cd1e05 MH |
172 | voluntarily giving up the processor before its time slice was |
173 | completed (usually to await availability of a resource). | |
174 | .TP | |
175 | .IR ru_nivcsw " (since Linux 2.6)" | |
57440a98 | 176 | The number of times a context switch resulted due to a higher |
d1cd1e05 MH |
177 | priority process becoming runnable or because the current process |
178 | exceeded its time slice. | |
179 | .PP | |
e3a887db | 180 | .SH "RETURN VALUE" |
c13182ef MK |
181 | On success, zero is returned. |
182 | On error, \-1 is returned, and | |
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183 | .I errno |
184 | is set appropriately. | |
185 | .SH ERRORS | |
186 | .TP | |
187 | .B EFAULT | |
188 | .I usage | |
189 | points outside the accessible address space. | |
190 | .TP | |
191 | .B EINVAL | |
192 | .I who | |
193 | is invalid. | |
194 | .SH "CONFORMING TO" | |
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195 | SVr4, 4.3BSD. |
196 | POSIX.1-2001 specifies | |
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197 | .BR getrusage (), |
198 | but only specifies the fields | |
199 | .I ru_utime | |
200 | and | |
201 | .IR ru_stime . | |
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202 | |
203 | .B RUSAGE_THREAD | |
204 | is Linux-specific. | |
e3a887db | 205 | .SH NOTES |
dfcc37a6 MK |
206 | Resource usage metrics are preserved across an |
207 | .BR execve (2). | |
208 | ||
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209 | Including |
210 | .I <sys/time.h> | |
211 | is not required these days, but increases portability. | |
212 | (Indeed, | |
213 | .I struct timeval | |
214 | is defined in | |
215 | .IR <sys/time.h> .) | |
216 | .PP | |
217 | In Linux kernel versions before 2.6.9, if the disposition of | |
218 | .B SIGCHLD | |
219 | is set to | |
220 | .B SIG_IGN | |
221 | then the resource usages of child processes | |
222 | are automatically included in the value returned by | |
223 | .BR RUSAGE_CHILDREN , | |
97c1eac8 | 224 | although POSIX.1-2001 explicitly prohibits this. |
cfea5132 | 225 | This nonconformance is rectified in Linux 2.6.9 and later. |
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226 | .\" See the description of getrusage() in XSH. |
227 | .\" A similar statement was also in SUSv2. | |
228 | .LP | |
bc5ec131 MK |
229 | The structure definition shown at the start of this page |
230 | was taken from 4.3BSD Reno. | |
94ce95ef MK |
231 | |
232 | See also the description of | |
233 | .IR /proc/PID/stat | |
234 | in | |
235 | .BR proc (5). | |
e3a887db | 236 | .SH "SEE ALSO" |
0eb44391 | 237 | .BR clock_gettime (2), |
e3a887db MK |
238 | .BR getrlimit (2), |
239 | .BR times (2), | |
240 | .BR wait (2), | |
0302f101 | 241 | .BR wait4 (2), |
0eb44391 | 242 | .BR clock (3) |