STREAMS-UX Programmer's Guide (February 2007)

Appendix H
297
H STREAMS Kernel Tunable Parameters
Overview
The following kernel parameters can be configured and used for managing the resources used by STREAMS.
NSTREVENT Maximum number of outstanding streams bufcalls that are allowed to exist at any given
time. This number should be greater than or equal to the maximum number of bufcalls that
can be generated by all modules pushed onto a given stream. This serves to limit runaway
bufcalls.
NSTRPUSH Maximum number of streams modules that are allowed to exist in any single stream at any
given time. This provides a mechanism for preventing a software defect from attempting to
push too many modules onto a stream. It does not protect against the malicious use of
streams.
NSTRSCHED Maximum number of streams scheduler daemons that are allowed to run at any given time.
This value is related to the number of processors installed in the system.
STRCTLSZ Maximum number of control bytes allowed in the control portion of any streams message.
STRMSGSZ Maximum number of bytes that can be placed in the data portion of any streams message.
streampipes Maximum number of bytes that can be placed in the data portion of any streams message.
These kernel tunable parameters can be either modified with SAM or by using the kctune(1M) command.
The details for each of these kernel tunable parameters are provided in the following manpages.