sysinfo(2) — Linux manual page

sysinfo(2)                 System Calls Manual                sysinfo(2)

NAME

       sysinfo - return system information

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <sys/sysinfo.h>

       int sysinfo(struct sysinfo *info);

DESCRIPTION

       sysinfo() returns certain statistics on memory and swap usage, as
       well as the load average.

       Until Linux 2.3.16, sysinfo() returned information in the
       following structure:

           struct sysinfo {
               long uptime;             /* Seconds since boot */
               unsigned long loads[3];  /* 1, 5, and 15 minute load averages */
               unsigned long totalram;  /* Total usable main memory size */
               unsigned long freeram;   /* Available memory size */
               unsigned long sharedram; /* Amount of shared memory */
               unsigned long bufferram; /* Memory used by buffers */
               unsigned long totalswap; /* Total swap space size */
               unsigned long freeswap;  /* Swap space still available */
               unsigned short procs;    /* Number of current processes */
               char _f[22];             /* Pads structure to 64 bytes */
           };

       In the above structure, the sizes of the memory and swap fields
       are given in bytes.

       Since Linux 2.3.23 (i386) and Linux 2.3.48 (all architectures)
       the structure is:

           struct sysinfo {
               long uptime;             /* Seconds since boot */
               unsigned long loads[3];  /* 1, 5, and 15 minute load averages */
               unsigned long totalram;  /* Total usable main memory size */
               unsigned long freeram;   /* Available memory size */
               unsigned long sharedram; /* Amount of shared memory */
               unsigned long bufferram; /* Memory used by buffers */
               unsigned long totalswap; /* Total swap space size */
               unsigned long freeswap;  /* Swap space still available */
               unsigned short procs;    /* Number of current processes */
               unsigned long totalhigh; /* Total high memory size */
               unsigned long freehigh;  /* Available high memory size */
               unsigned int mem_unit;   /* Memory unit size in bytes */
               char _f[20-2*sizeof(long)-sizeof(int)];
                                        /* Padding to 64 bytes */
           };

       In the above structure, sizes of the memory and swap fields are
       given as multiples of mem_unit bytes.

RETURN VALUE

       On success, sysinfo() returns zero.  On error, -1 is returned,
       and errno is set to indicate the error.

ERRORS

       EFAULT info is not a valid address.

STANDARDS

       Linux.

HISTORY

       Linux 0.98.pl6.

NOTES

       All of the information provided by this system call is also
       available via /proc/meminfo and /proc/loadavg.

SEE ALSO

       proc(5)

COLOPHON

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Linux man-pages 6.9.1          2024-05-02                     sysinfo(2)

Pages that refer to this page: syscalls(2), get_phys_pages(3)

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