SDMOPT parameter
SDaemon options
Summary
- Default value
- X'03'
- Parameter type
- System
- Where set
- User 0 CCAIN parameters, or reset by a System Manager
- Related products
- All
- Introduced
- Sirius Mods 6.7
Description
This User 0 system parameter is a bitmask parameter that affects sdaemon processing. The meaning of the bits are:
- X'01'
- Server tables are not to be cleared at user login, logout, or UTABLE commands. While clearing of user tables is “nice” in some sense, since daemons tend to do a lot of logging in and out and a lot of UTABLE commands, this niceness can have a high CPU cost. Other than being “nice” there is little benefit to clearing all the server tables at these points.
- X'02'
- Do optimized file and group opens and closes when entering or exiting a subsystem. Since daemons that use APSY subsystems have a high ratio of subsystem exit/entry to subsystem processing, reducing this overhead can be a great CPU savings.
The default for SDMOPT of X'03' means that all the sdaemon optimizations are enabled. There should be no reason to disable any optimizations unless one is suspected of causing a bug.