1SYSINFO(2) Linux Programmer's Manual SYSINFO(2)
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6 sysinfo - return system information
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9 #include <sys/sysinfo.h>
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11 int sysinfo(struct sysinfo *info);
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14 sysinfo() returns certain statistics on memory and swap usage, as well
15 as the load average.
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17 Until Linux 2.3.16, sysinfo() returned information in the following
18 structure:
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20 struct sysinfo {
21 long uptime; /* Seconds since boot */
22 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
23 unsigned long totalram; /* Total usable main memory size */
24 unsigned long freeram; /* Available memory size */
25 unsigned long sharedram; /* Amount of shared memory */
26 unsigned long bufferram; /* Memory used by buffers */
27 unsigned long totalswap; /* Total swap space size */
28 unsigned long freeswap; /* Swap space still available */
29 unsigned short procs; /* Number of current processes */
30 char _f[22]; /* Pads structure to 64 bytes */
31 };
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33 In the above structure, the sizes of the memory and swap fields are
34 given in bytes.
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36 Since Linux 2.3.23 (i386) and Linux 2.3.48 (all architectures) the
37 structure is:
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39 struct sysinfo {
40 long uptime; /* Seconds since boot */
41 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
42 unsigned long totalram; /* Total usable main memory size */
43 unsigned long freeram; /* Available memory size */
44 unsigned long sharedram; /* Amount of shared memory */
45 unsigned long bufferram; /* Memory used by buffers */
46 unsigned long totalswap; /* Total swap space size */
47 unsigned long freeswap; /* Swap space still available */
48 unsigned short procs; /* Number of current processes */
49 unsigned long totalhigh; /* Total high memory size */
50 unsigned long freehigh; /* Available high memory size */
51 unsigned int mem_unit; /* Memory unit size in bytes */
52 char _f[20-2*sizeof(long)-sizeof(int)];
53 /* Padding to 64 bytes */
54 };
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56 In the above structure, sizes of the memory and swap fields are given
57 as multiples of mem_unit bytes.
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60 On success, sysinfo() returns zero. On error, -1 is returned, and
61 errno is set to indicate the cause of the error.
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64 EFAULT info is not a valid address.
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67 sysinfo() first appeared in Linux 0.98.pl6.
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70 This function is Linux-specific, and should not be used in programs
71 intended to be portable.
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74 All of the information provided by this system call is also available
75 via /proc/meminfo and /proc/loadavg.
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78 proc(5)
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81 This page is part of release 4.15 of the Linux man-pages project. A
82 description of the project, information about reporting bugs, and the
83 latest version of this page, can be found at
84 https://www.kernel.org/doc/man-pages/.
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88Linux 2017-09-15 SYSINFO(2)