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 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 4.15 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)