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

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.