NAME¶

sysinfo - return system information

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 cause of the error.

ERRORS¶

EFAULT

info is not a valid address.

VERSIONS¶

sysinfo() first appeared in Linux 0.98.pl6.

CONFORMING TO¶

This function is Linux-specific, and should not be used in programs intended to be portable.

NOTES¶

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

SEE ALSO¶

proc(5)

COLOPHON¶

This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.