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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 follow-
       ing 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 portable 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
CONFORMING TO
       This function is Linux-specific, and should not  be  used  in  programs
       intended to be portable.
       The  Linux  kernel  has  a sysinfo() system call since 0.98.pl6.  Linux
       libc contains a sysinfo() routine since 5.3.5, and glibc has one  since
       1.90.
SEE ALSO
       proc(5)
COLOPHON
       This  page  is  part of release 3.53 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

Linux                             2012-05-05                        SYSINFO(2)