AT&T UNIX™PC Unix System V Users Manual - tenox

KTUNE(7)
nclist
npbuf
ncall
nttyhog
kern=
KTUNE(7)
Number of clist buffers available. These buffers are used
mostly by character device drivers for terminal 110 operations.
Range: 32 up to system capacity.
Number of buffer headers available in the raw IIO pool of
headers.
Range: 4 up to system capacity.
Number of callouts allowed in the kernel. When a process
must be sure that it is awakened after a specific period of
time, it calls the kernel timeout routine with a specified
amount of time. The timeout routine places an entry in the
callout table. ncall specifies the number of entries in the
callout table.
Range: 16 up to system capacity.
Maximum number of characters outstanding in the tty
buffer for a given port before the system will flush that
port's queue. If this value is set to 0, the system will no
longer check for the maximum characters outstanding in
the buffers. The ttyhog option keeps one port from using
all the clist buffers, ensuring that each port has enough
buffer space.
Range: 0 up to 1024
If an argument 'kern=filename' is present, the program
modifies file 'filename' instead of /unix.
ktune commands that list only some of the parameters cause only those
parameters to change. An argument consisting of a dash (-) is taken to
be a file name corresponding to the standard input. The options may
appear in any order but must appear before the files.
The -d flag lists each parameter and the value which the kernel is
currently using. Note that this might be different than the setting on the
actual file on disk. Each parameter appears on a separate line, with the
value preceded by a keyword (i.e., ninode=200). Input lists that list only
some of the parameters cause only those parameters to change. This
option displays the actual settings in use for the running kernel (not the
settings stored on the disk). These settings may be lower than the disk
settings due to small memory size.
The -r option resets parameters to their default values as specified in the
/etc/master file.
There is a table called 'tuhi' which resides in the kernel. Tuning is
accomplished by changing the parameters in this table on the disk, and
requires the user to reboot.
All input parameters are checked against a set of minimum parameters.
Any input with an error on any parameter results in no changes to any
parameters. Input lists containing a value that violates these minimums
result in no changes, and an error return.
The kernel boot routine is modified to provide for sanity checking on
boot up to insure that enough memory is present for the values specified,
and that the kernel virtual memory addressing limits are not violated. If
the memory found is too small for the values in 'tuhi', the values in core
(not on the disk) are adjusted downward until the resulting kernel runs on
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