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



NAME
       sysinfo - returns information on overall system statistics

SYNOPSIS
       #include <sys/sysinfo.h>

       int sysinfo(struct sysinfo *info);

DESCRIPTION
       Until Linux 2.3.16, sysinfo() used to return 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 */
           };

       and the sizes were given in bytes.

       Since Linux 2.3.23 (i386), 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 */
           };

       and the sizes are given as multiples of mem_unit bytes.

       sysinfo() provides a simple way of getting overall system statistics.  This is more porta‐
       ble than reading /dev/kmem.

RETURN VALUE
       On success, zero is returned.  On error, -1 is returned, and errno is set appropriately.

ERRORS
       EFAULT pointer to struct sysinfo is invalid

VERSIONS
       The Linux kernel has a sysinfo() system call since 0.98.pl6.

CONFORMING TO
       This function is Linux-specific, and should not be used in programs intended to be  porta‐
       ble.

SEE ALSO
       proc(5)

COLOPHON
       This  page  is  part of release 3.74 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 http://www.kernel.org/doc/man-pages/.



Linux                                       2014-08-19                                 SYSINFO(2)