sysinfo(2) - Linux manual page (original) (raw)

sysinfo(2) System Calls Manual sysinfo(2)

NAME top

   sysinfo - return system information

LIBRARY top

   Standard C library (_libc_, _-lc_)

SYNOPSIS top

   **#include <sys/sysinfo.h>**

   **int sysinfo(struct sysinfo ***_info_**);**

DESCRIPTION top

   **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 _memunit_ bytes.

RETURN VALUE top

   On success, **sysinfo**() returns zero.  On error, -1 is returned, and
   _[errno](../man3/errno.3.html)_ is set to indicate the error.

ERRORS top

   **EFAULT** _info_ is not a valid address.

STANDARDS top

   Linux.

HISTORY top

   Linux 0.98.pl6.

NOTES top

   All of the information provided by this system call is also
   available via _/proc/meminfo_ and _/proc/loadavg_.

SEE ALSO top

   [proc(5)](../man5/proc.5.html)

COLOPHON top

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Linux man-pages 6.10 2024-07-23 sysinfo(2)

Pages that refer to this page:syscalls(2), get_phys_pages(3)