Autotune(4dsp)
Autotune --
autotuning tunable parameter definitions
Synopsis
Autotune
Description
One of the Installable Driver/Tunable Parameters kernel configuration files,
an Autotune file, contains definitions for the default, minimum,
and maximum values for tunables that should change with the amount of
memory present.
Lines in the /etc/conf/cf.d/mtune file are
created for these variables based on this information.
The information
is also passed to the kernel as a structure in the
/etc/conf/pack.d/module-name/tune.c file.
This is used to retune the tunable at boot,
if the memory size has changed.
The autotuning can be overridden by using idtune(1M).
Autotune files
exist on a per-module basis, for those modules that have autotuned
parameters.
idinstall(1M)
stores the module's
Autotune file information in
/etc/conf/autotune.d/module-name,
where the file module-name is the name of the module
being installed.
Package scripts should never access /etc/conf/autotune.d
files directly;
only the idinstall and idtune commands should be used.
Each tunable is specified on multiple lines of the form:
parameter-name min-max-or-default linear-or-step memsize value
All fields are positional and must be separated by white space. Blank
lines and lines beginning with ``#'' or ``*'' are
considered comments and ignored.
The Autotune file fields are:
- parameter-name
-
A string (maximum of 20 characters) used as the parameter-name in the
mtune file line constructed.
- min-max-or-default
-
A string used to specify whether this line pertains to the
default value (DEF), minimum value (MIN),
or maximum value (MAX) in the
mtune file line constructed.
- linear-or-step
-
The string LINEAR or
STEP, used to determine how to calculate the value
for memory sizes in between those specified.
Linear will use linear interpolation between the two closest points,
or linear extrapolation from the last two points if the
largest memory size specified is smaller than the amount of memory
in the system and has LINEAR specified.
STEP will use the value
from the next smaller memory size.
- memsize
-
The memory size, in megabytes, for which this line specifies
the tunable's minimum, maximum, or default value.
- value
-
The value to be assigned to the tunable's minimum, maximum, or default
value at the given memory size.
For detailed information on Autotune parameters, refer to the
tunable parameters chapter in your system
administration documentation.
References
idbuild(1M),
idinstall(1M),
idtune(1M),
Mtune(4dsp),
Space.c(4dsp),
stune(4dsp)
30 January 1998
© 1998 The Santa Cruz Operation, Inc. All rights reserved.