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a1eaacb1 | 1 | '\" t |
e3a887db | 2 | .\" Copyright (c) 1992 Drew Eckhardt, March 28, 1992 |
6883b3e7 | 3 | .\" and Copyright (c) 2002 Michael Kerrisk |
e3a887db | 4 | .\" |
5fbde956 | 5 | .\" SPDX-License-Identifier: Linux-man-pages-copyleft |
e3a887db | 6 | .\" |
c13182ef MK |
7 | .\" 2004-11-16 -- mtk: the getrlimit.2 page, which formerly included |
8 | .\" coverage of getrusage(2), has been split, so that the latter is | |
9 | .\" now covered in its own getrusage.2. For older details of change | |
0967c11f | 10 | .\" history, etc., see getrlimit.2 |
e3a887db | 11 | .\" |
cfea5132 | 12 | .\" Modified 2004-11-16, mtk, Noted that the nonconformance |
b324e17d | 13 | .\" when SIGCHLD is being ignored is fixed in Linux 2.6.9. |
94ce95ef MK |
14 | .\" 2008-02-22, Sripathi Kodi <sripathik@in.ibm.com>: Document RUSAGE_THREAD |
15 | .\" 2008-05-25, mtk, clarify RUSAGE_CHILDREN + other clean-ups. | |
e3f4bf3e MK |
16 | .\" 2010-05-24, Mark Hills <mark@pogo.org.uk>: Description of fields, |
17 | .\" document ru_maxrss | |
57440a98 | 18 | .\" 2010-05-24, mtk, enhanced description of various fields |
e3a887db | 19 | .\" |
4c1c5274 | 20 | .TH getrusage 2 (date) "Linux man-pages (unreleased)" |
e3a887db MK |
21 | .SH NAME |
22 | getrusage \- get resource usage | |
c72cd69a AC |
23 | .SH LIBRARY |
24 | Standard C library | |
8fc3b2cf | 25 | .RI ( libc ", " \-lc ) |
e3a887db | 26 | .SH SYNOPSIS |
c7db92b9 | 27 | .nf |
e3a887db | 28 | .B #include <sys/resource.h> |
68e4db0a | 29 | .PP |
e3a887db | 30 | .BI "int getrusage(int " who ", struct rusage *" usage ); |
c7db92b9 | 31 | .fi |
e3a887db | 32 | .SH DESCRIPTION |
e3a887db | 33 | .BR getrusage () |
94ce95ef MK |
34 | returns resource usage measures for |
35 | .IR who , | |
36 | which can be one of the following: | |
37 | .TP | |
2914a14d MK |
38 | .B RUSAGE_SELF |
39 | Return resource usage statistics for the calling process, | |
94ce95ef MK |
40 | which is the sum of resources used by all threads in the process. |
41 | .TP | |
2914a14d | 42 | .B RUSAGE_CHILDREN |
94ce95ef MK |
43 | Return resource usage statistics for all children of the |
44 | calling process that have terminated and been waited for. | |
45 | These statistics will include the resources used by grandchildren, | |
46 | and further removed descendants, | |
47 | if all of the intervening descendants waited on their terminated children. | |
48 | .TP | |
49 | .BR RUSAGE_THREAD " (since Linux 2.6.26)" | |
50 | Return resource usage statistics for the calling thread. | |
1205c845 MK |
51 | The |
52 | .B _GNU_SOURCE | |
53 | feature test macro must be defined (before including | |
54 | .I any | |
55 | header file) | |
56 | in order to obtain the definition of this constant from | |
57 | .IR <sys/resource.h> . | |
94ce95ef MK |
58 | .PP |
59 | The resource usages are returned in the structure pointed to by | |
60 | .IR usage , | |
61 | which has the following form: | |
c13182ef | 62 | .PP |
a08ea57c | 63 | .in +4n |
03bd5415 | 64 | .EX |
e3a887db | 65 | struct rusage { |
57440a98 MK |
66 | struct timeval ru_utime; /* user CPU time used */ |
67 | struct timeval ru_stime; /* system CPU time used */ | |
e3a887db MK |
68 | long ru_maxrss; /* maximum resident set size */ |
69 | long ru_ixrss; /* integral shared memory size */ | |
70 | long ru_idrss; /* integral unshared data size */ | |
71 | long ru_isrss; /* integral unshared stack size */ | |
57440a98 MK |
72 | long ru_minflt; /* page reclaims (soft page faults) */ |
73 | long ru_majflt; /* page faults (hard page faults) */ | |
e3a887db MK |
74 | long ru_nswap; /* swaps */ |
75 | long ru_inblock; /* block input operations */ | |
76 | long ru_oublock; /* block output operations */ | |
57440a98 MK |
77 | long ru_msgsnd; /* IPC messages sent */ |
78 | long ru_msgrcv; /* IPC messages received */ | |
e3a887db MK |
79 | long ru_nsignals; /* signals received */ |
80 | long ru_nvcsw; /* voluntary context switches */ | |
81 | long ru_nivcsw; /* involuntary context switches */ | |
82 | }; | |
03bd5415 | 83 | .EE |
a08ea57c | 84 | .in |
d1cd1e05 | 85 | .PP |
14f1e036 MK |
86 | Not all fields are completed; |
87 | unmaintained fields are set to zero by the kernel. | |
88 | (The unmaintained fields are provided for compatibility with other systems, | |
89 | and because they may one day be supported on Linux.) | |
90 | The fields are interpreted as follows: | |
d1cd1e05 MH |
91 | .TP |
92 | .I ru_utime | |
57440a98 MK |
93 | This is the total amount of time spent executing in user mode, |
94 | expressed in a | |
95 | .I timeval | |
96 | structure (seconds plus microseconds). | |
d1cd1e05 MH |
97 | .TP |
98 | .I ru_stime | |
57440a98 MK |
99 | This is the total amount of time spent executing in kernel mode, |
100 | expressed in a | |
101 | .I timeval | |
102 | structure (seconds plus microseconds). | |
d1cd1e05 | 103 | .TP |
c90ccb4e | 104 | .IR ru_maxrss " (since Linux 2.6.32)" |
e3948c69 MK |
105 | This is the maximum resident set size used (in kilobytes). |
106 | For | |
57440a98 | 107 | .BR RUSAGE_CHILDREN , |
c90ccb4e MH |
108 | this is the resident set size of the largest child, not the maximum |
109 | resident set size of the process tree. | |
d1cd1e05 MH |
110 | .TP |
111 | .IR ru_ixrss " (unmaintained)" | |
14f1e036 MK |
112 | This field is currently unused on Linux. |
113 | .\" On some systems, | |
114 | .\" this is the integral of the text segment memory consumption, | |
115 | .\" expressed in kilobyte-seconds. | |
d1cd1e05 MH |
116 | .TP |
117 | .IR ru_idrss " (unmaintained)" | |
14f1e036 MK |
118 | This field is currently unused on Linux. |
119 | .\" On some systems, this is the integral of the data segment memory consumption, | |
120 | .\" expressed in kilobyte-seconds. | |
d1cd1e05 MH |
121 | .TP |
122 | .IR ru_isrss " (unmaintained)" | |
14f1e036 MK |
123 | This field is currently unused on Linux. |
124 | .\" On some systems, this is the integral of the stack memory consumption, | |
125 | .\" expressed in kilobyte-seconds. | |
d1cd1e05 MH |
126 | .TP |
127 | .I ru_minflt | |
57440a98 | 128 | The number of page faults serviced without any I/O activity; here |
d1cd1e05 MH |
129 | I/O activity is avoided by \*(lqreclaiming\*(rq a page frame from |
130 | the list of pages awaiting reallocation. | |
131 | .TP | |
132 | .I ru_majflt | |
57440a98 | 133 | The number of page faults serviced that required I/O activity. |
d1cd1e05 MH |
134 | .TP |
135 | .IR ru_nswap " (unmaintained)" | |
14f1e036 MK |
136 | This field is currently unused on Linux. |
137 | .\" On some systems, this is the number of swaps out of physical memory. | |
d1cd1e05 MH |
138 | .TP |
139 | .IR ru_inblock " (since Linux 2.6.22)" | |
9ee4a2b6 | 140 | The number of times the filesystem had to perform input. |
d1cd1e05 MH |
141 | .TP |
142 | .IR ru_oublock " (since Linux 2.6.22)" | |
9ee4a2b6 | 143 | The number of times the filesystem had to perform output. |
d1cd1e05 MH |
144 | .TP |
145 | .IR ru_msgsnd " (unmaintained)" | |
14f1e036 | 146 | This field is currently unused on Linux. |
87f8e275 | 147 | .\" On FreeBSD 6.2, this appears to measure messages sent over sockets |
14f1e036 MK |
148 | .\" On some systems, |
149 | .\" this field records the number of messages sent over sockets. | |
d1cd1e05 MH |
150 | .TP |
151 | .IR ru_msgrcv " (unmaintained)" | |
14f1e036 | 152 | This field is currently unused on Linux. |
87f8e275 | 153 | .\" On FreeBSD 6.2, this appears to measure messages received over sockets |
14f1e036 MK |
154 | .\" On some systems, |
155 | .\" this field records the number of messages received over sockets. | |
d1cd1e05 MH |
156 | .TP |
157 | .IR ru_nsignals " (unmaintained)" | |
14f1e036 MK |
158 | This field is currently unused on Linux. |
159 | .\" On some systems, this field records the number of signals received. | |
d1cd1e05 MH |
160 | .TP |
161 | .IR ru_nvcsw " (since Linux 2.6)" | |
57440a98 | 162 | The number of times a context switch resulted due to a process |
d1cd1e05 MH |
163 | voluntarily giving up the processor before its time slice was |
164 | completed (usually to await availability of a resource). | |
165 | .TP | |
166 | .IR ru_nivcsw " (since Linux 2.6)" | |
57440a98 | 167 | The number of times a context switch resulted due to a higher |
d1cd1e05 MH |
168 | priority process becoming runnable or because the current process |
169 | exceeded its time slice. | |
47297adb | 170 | .SH RETURN VALUE |
c13182ef MK |
171 | On success, zero is returned. |
172 | On error, \-1 is returned, and | |
e3a887db | 173 | .I errno |
f6a4078b | 174 | is set to indicate the error. |
e3a887db MK |
175 | .SH ERRORS |
176 | .TP | |
177 | .B EFAULT | |
178 | .I usage | |
179 | points outside the accessible address space. | |
180 | .TP | |
181 | .B EINVAL | |
182 | .I who | |
183 | is invalid. | |
47e94221 ZL |
184 | .SH ATTRIBUTES |
185 | For an explanation of the terms used in this section, see | |
186 | .BR attributes (7). | |
187 | .TS | |
188 | allbox; | |
c466875e | 189 | lbx lb lb |
47e94221 ZL |
190 | l l l. |
191 | Interface Attribute Value | |
192 | T{ | |
9e54434e BR |
193 | .na |
194 | .nh | |
47e94221 ZL |
195 | .BR getrusage () |
196 | T} Thread safety MT-Safe | |
197 | .TE | |
efeece04 | 198 | .sp 1 |
3113c7f3 | 199 | .SH STANDARDS |
4131356c AC |
200 | POSIX.1-2008. |
201 | .PP | |
3973434f | 202 | POSIX.1 specifies |
97c1eac8 | 203 | .BR getrusage (), |
33a0ccb2 | 204 | but specifies only the fields |
97c1eac8 MK |
205 | .I ru_utime |
206 | and | |
207 | .IR ru_stime . | |
efeece04 | 208 | .PP |
94ce95ef MK |
209 | .B RUSAGE_THREAD |
210 | is Linux-specific. | |
4131356c AC |
211 | .SH HISTORY |
212 | POSIX.1-2001, SVr4, 4.3BSD. | |
efeece04 | 213 | .PP |
b324e17d | 214 | Before Linux 2.6.9, if the disposition of |
e3a887db MK |
215 | .B SIGCHLD |
216 | is set to | |
217 | .B SIG_IGN | |
218 | then the resource usages of child processes | |
219 | are automatically included in the value returned by | |
220 | .BR RUSAGE_CHILDREN , | |
97c1eac8 | 221 | although POSIX.1-2001 explicitly prohibits this. |
cfea5132 | 222 | This nonconformance is rectified in Linux 2.6.9 and later. |
e3a887db MK |
223 | .\" See the description of getrusage() in XSH. |
224 | .\" A similar statement was also in SUSv2. | |
dd3568a1 | 225 | .PP |
bc5ec131 MK |
226 | The structure definition shown at the start of this page |
227 | was taken from 4.3BSD Reno. | |
efeece04 | 228 | .PP |
8a18a944 MK |
229 | Ancient systems provided a |
230 | .BR vtimes () | |
231 | function with a similar purpose to | |
232 | .BR getrusage (). | |
b324e17d | 233 | For backward compatibility, glibc (up until Linux 2.32) also provides |
8a18a944 MK |
234 | .BR vtimes (). |
235 | All new applications should be written using | |
236 | .BR getrusage (). | |
b324e17d | 237 | (Since Linux 2.33, glibc no longer provides an |
c751bb1e MK |
238 | .BR vtimes () |
239 | implementation.) | |
4131356c AC |
240 | .SH NOTES |
241 | Resource usage metrics are preserved across an | |
242 | .BR execve (2). | |
efeece04 | 243 | .PP |
94ce95ef | 244 | See also the description of |
1ae6b2c7 | 245 | .IR /proc/ pid /stat |
94ce95ef MK |
246 | in |
247 | .BR proc (5). | |
47297adb | 248 | .SH SEE ALSO |
0eb44391 | 249 | .BR clock_gettime (2), |
e3a887db MK |
250 | .BR getrlimit (2), |
251 | .BR times (2), | |
252 | .BR wait (2), | |
0302f101 | 253 | .BR wait4 (2), |
0eb44391 | 254 | .BR clock (3) |