1SYSINFO(2)                 Linux Programmer's Manual                SYSINFO(2)
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NAME

6       sysinfo - returns information on overall system statistics
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SYNOPSIS

9       #include <sys/sysinfo.h>
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11       int sysinfo(struct sysinfo *info);
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DESCRIPTION

14       Until Linux 2.3.16, sysinfo() used to return information in the follow‐
15       ing structure:
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17           struct sysinfo {
18               long uptime;             /* Seconds since boot */
19               unsigned long loads[3];  /* 1, 5, and 15 minute load averages */
20               unsigned long totalram;  /* Total usable main memory size */
21               unsigned long freeram;   /* Available memory size */
22               unsigned long sharedram; /* Amount of shared memory */
23               unsigned long bufferram; /* Memory used by buffers */
24               unsigned long totalswap; /* Total swap space size */
25               unsigned long freeswap;  /* swap space still available */
26               unsigned short procs;    /* Number of current processes */
27               char _f[22];             /* Pads structure to 64 bytes */
28           };
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30       and the sizes were given in bytes.
31
32       Since Linux 2.3.23 (i386), 2.3.48 (all architectures) the structure is:
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34           struct sysinfo {
35               long uptime;             /* Seconds since boot */
36               unsigned long loads[3];  /* 1, 5, and 15 minute load averages */
37               unsigned long totalram;  /* Total usable main memory size */
38               unsigned long freeram;   /* Available memory size */
39               unsigned long sharedram; /* Amount of shared memory */
40               unsigned long bufferram; /* Memory used by buffers */
41               unsigned long totalswap; /* Total swap space size */
42               unsigned long freeswap;  /* swap space still available */
43               unsigned short procs;    /* Number of current processes */
44               unsigned long totalhigh; /* Total high memory size */
45               unsigned long freehigh;  /* Available high memory size */
46               unsigned int mem_unit;   /* Memory unit size in bytes */
47               char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding to 64 bytes */
48           };
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50       and the sizes are given as multiples of mem_unit bytes.
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52       sysinfo() provides a simple way of getting overall  system  statistics.
53       This is more portable than reading /dev/kmem.
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RETURN VALUE

56       On  success,  zero is returned.  On error, -1 is returned, and errno is
57       set appropriately.
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ERRORS

60       EFAULT pointer to struct sysinfo is invalid
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CONFORMING TO

63       This function is Linux-specific, and should not  be  used  in  programs
64       intended to be portable.
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66       The  Linux  kernel  has  a sysinfo() system call since 0.98.pl6.  Linux
67       libc contains a sysinfo() routine since 5.3.5, and glibc has one  since
68       1.90.
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SEE ALSO

71       proc(5)
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COLOPHON

74       This  page  is  part of release 3.53 of the Linux man-pages project.  A
75       description of the project, and information about reporting  bugs,  can
76       be found at http://www.kernel.org/doc/man-pages/.
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80Linux                             2012-05-05                        SYSINFO(2)
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