sysinfo

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  er-
       rno 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 in-
       tended 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 5.05 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/.

Linux                             2017-09-15                        SYSINFO(2)