Tunable Parameters

Certain system parameters referred to by STREAMS are configurable when building a new operating system (see the file /etc/system and the SunOS User's Guide to System Administration for further details). These parameters are:

nstrpush

Maximum number (should be at least 8) of modules that can be pushed onto a single stream.

strmsgsz

Maximum number of bytes of information that a single system call can pass to a stream to be placed into the data part of a message (in M_DATA blocks). Any write(2) exceeding this size is broken into multiple messages. A putmsg(2) with a data part exceeding this size fails with ERANGE. If STRMSGSZ is set to 0, the number of bytes passed to a stream is infinite.

strctlsz

Maximum number of bytes of information that a single system call can pass to a stream to be placed into the control part of a message (in an M_PROTO or M_PCPROTO block). A putmsg(2) with a control part that exceeds this size fails with ERANGE.