Understanding coupling facility use of processor resources

Both the cache and the list structure use resources in the processor to which the coupling facility is attached. These resources, in HSA, are allocated to the processor at processor initialization time and cannot be modified during sysplex processing. Specifically, the structure use of processor resources is:

The local cache vector is a user-defined vector that provides a way for cache structure users to determine the validity of data in their local cache vectors. There is one local cache vector per user of the cache structure. Each vector is divided into separate entries with each entry corresponding to a local cache buffer. Each vector entry contains an indicator that the system sets to indicate whether the data in the corresponding local cache vector is valid. Users must test the indicator to determine the validity of the data in their local cache buffers.
The list notification vector is a user-defined vector that provides a way for list structure users to determine the state (empty or nonempty) of each list or event queue they are monitoring. Each connector to a list structure that indicates interest in list or event queue monitoring is allocated a list notification vector. The vector consists of an array of entries, each of which can be associated with a particular list header or the user's event queue. Each entry contains an indicator that the system sets to indicate the empty or nonempty state of the list or event queue.

XES provides the IXLVECTR service to examine the contents of the vectors allocated in HSA, but the service does not allow you to free up the vectors. Vectors that are allocated in HSA are freed up when connectors disconnect, but remain there in error scenarios such as when a system failure occurs. The implication of having obsolete vectors remaining in HSA is that the subsystems that require the allocation of vectors might not be able to initialize if additional HSA storage is not available.

To clear the obsolete vectors from HSA, the system must be reset with either a LOAD or SYSRESET command. On all processors, the LOAD CLEAR or SYSRESET CLEAR command can be used to clear the unused, obsolete vectors from HSA. On some processors, the LOAD NORMAL and SYSRESET NORMAL function has been enhanced to clear the vectors from HSA.

If you are running on a processor that has not been upgraded to allow the clearing of obsolete vectors from HSA, use the LOAD CLEAR or SYSRESET CLEAR command to clear the vector space.
If you are running on a processor that has been upgraded to allow the clearing of obsolete vectors from HSA, use the LOAD NORMAL or SYSRESET NORMAL command to clear the vector space.

See the applicable Operations Guide for your processor for a description of the LOAD and SYSRESET commands.