Tuning

The tuning of a system running XCICS/TS involves on:

•	IPC resources

•	shared memory

Inter-Process Communication resources

XCICS/TS processes inter-communicate by IPC resources (semaphores and message queues). To ensure a correct IPC communication into the region some system parameters must be set.

The values are strictly dependand on OS and H/W architecture. This table contains only suggested values.

parameter	value
semmsl	256
semmns	32000
semopm	100
semmni	128
msgseg	32767
shmmni	4096

Shared memory availability

A sufficient amount of shared memory must be available for each XCICS/TS region.

The amount of shared memory required by a region depends on:

•	number of entries in the resource tables (PCT, PPT, etc)

•	size of the main storage reserved for user programs (GETMAIN), as requested in the region configuration file.

When the region starts up, it shows, in the main console log, the amount or requested shared memory and tries to allocate it. If the allocation fails, the region startup fails.

In this situation, the kernel of the system must be configured to allow the allocation of the amount of memory requested.