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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.

SEE ALSO

   proc(5)

COLOPHON

   This  page  is  part of release 4.09 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/.



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