focal (2) sysinfo.2.gz

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  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/.