HP-UX Reference (11i v1 05/09) - 2 System Calls (vol 5)

t
tuneinfo(2) tuneinfo(2)
NAME
tuneinfo - retrieve detailed information about kernel tunable parameters
SYNOPSIS
#include <sys/dyntune.h>
int tuneinfo(const char *tunable,
tuneinfo_t *buf,
size_t size,
int count);
DESCRIPTION
This function provides detailed information about one or all kernel tunable parameters. If a particular
parameter is of interest, specify it by name in tunable. Otherwise, set tunable to
NULL and information
will be returned on all kernel tunable parameters (up to the size of the supplied buffer).
Information about the selected tunable parameters is returned in
tuneinfo_t structures. buf must
specify an address in the caller’s space containing space for
count structures. The size of a tuneinfo_t
structure, as understood by the caller, should be passed in the size parameter.
Each tuneinfo_t structure describes a single tunable parameter, and contains at least the following
fields, in unspecified order:
char ti_name[TUNENAMELEN];
The name of the tunable parameter. NULL-terminated ASCII string.
char ti_desc[TUNEDESCLEN];
An English description of the parameter. NULL-terminated ASCII string.
char ti_mod[TUNEMODLEN];
The name of the DLKM module in which the parameter is defined. NULL-terminated ASCII
string. This will be a null string for those parameters defined in the core kernel.
uint64_t ti_current;
The current value of the parameter.
uint64_t ti_bootvalue;
The boot-time value of the parameter (compiled into the kernel).
uint64_t ti_default;
The HP-supplied default value of the parameter.
uint64_t ti_min;
The minimum value of the parameter. Valid only if the TIF_MINVALID flag is set in the
ti_flags word, below.
uint64_t ti_max;
The maximum value of the parameter. Valid only if the TIF_MAXVALID flag is set in the
ti_flags word, below.
Note: The minimum and maximum values returned here are relatively static limits. They will
reflect the limitations of the operating system software, and any limitations placed on this tun-
able parameter by the current values of other tunable parameters. However, they do not reflect
any restrictions on the tunable value based on transient factors like the current usage pattern of
the system.
For example, the maximum value returned for maxfiles (the number of files a process may
have open) will be no greater than the current value of nfile (the number of files the system
may have open). However, the minimum value returned for maxfiles may very well be less
than the number of files that some existing process has open.
unsigned ti_flags;
A bitmask of zero or more of the following flags:
TIF_CANSET The value of this parameter can be changed using settune().
TIF_DYNAMIC The value of this parameter can be changed using settune(), without
requiring a reboot.
TIF_SIGNED The values, minima and maxima, for this parameter should be interpreted as
signed quantities.
HP-UX 11i Version 1: September 2005 − 1 − Hewlett-Packard Company Section 2−−451