NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | SEE ALSO | COLOPHON
SYSINFO(2) Linux Programmer's Manual SYSINFO(2)
sysinfo - returns information on overall system statistics
#include <sys/sysinfo.h>
int sysinfo(struct sysinfo *info);
Until Linux 2.3.16, sysinfo() used to return 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 */
};
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 for libc5 */
};
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.
On success, zero is returned. On error, -1 is returned, and errno is set
appropriately.
EFAULT pointer to struct sysinfo is invalid
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.
proc(5)
This page is part of release 3.21 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 2007-11-15 SYSINFO(2)