sysinfo
Section: System Calls (2)
Updated: 202-0-08
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NAME
sysinfo - return system information
LIBRARY
Standard C library
(
libc,~
-lc)
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 error.
ERRORS
- EFAULT
-
info
is not a valid address.
STANDARDS
Linux.
HISTORY
Linux 0.98.pl6.
NOTES
All of the information provided by this system call is also available via
/proc/meminfo
and
/proc/loadavg.
SEE ALSO
proc(5)
Index
- NAME
-
- LIBRARY
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- STANDARDS
-
- HISTORY
-
- NOTES
-
- SEE ALSO
-
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