If the MUF startup option SMPTASK was specified, the following report can be useful for some tuning and in dealing with CA Support. Similar to the SMP dynamic system table, it provides information about statistics for the entire MUF run. This report is available to SQL and non-SQL sites. Most of the information reported reflects counts of SMP waiting conditions, and these fields cannot be changed by tuning.
Each POSTED ENTRY item reflects the depth counts of a POSTED LIST that provides information about how many tasks were ready to run at various times. Periodically, the posted list is scanned and the counter at the appropriate depth is incremented by one. This is not done often and the counts are not comparable to other counts. As a group, the counts provide a clue as to whether running in SMP mode would help or hurt, the number of SMPTASKs that might be selected, and the ready-to-run count. This information can be used to tune the ready-to-run option of the SMPTASK MUF startup option.
Note: Items in the report which have a zero count are skipped.
SMP INFORMATIONAL REPORT EVENT COUNT DXX BUFFER 266 DATA BUFFER 17 LOG BUFFER 15 LOG LRU 3 LOCK LIST 111 OPEN TABLE 1 TASK AREA 126 WAIT LIST 863 MEMORY MANAGER 23 PXX CONSOLE 1 POSTED ENTRY 0 8,029 POSTED ENTRY 1 7,243 POSTED ENTRY 2 3,368 POSTED ENTRY 3 3,649 POSTED ENTRY 4 4,048 POSTED ENTRY 5 4,348 POSTED ENTRY 6 4,811 POSTED ENTRY 7 5,299 POSTED ENTRY 8 5,735 POSTED ENTRY 9 6,448 POSTED ENTRY 10 7,594 POSTED ENTRY 11 9,368 POSTED ENTRY 12 10,870 POSTED ENTRY 13 10,815 POSTED ENTRY 14 10,013 POSTED ENTRY 15 9,230 POSTED ENTRY 16 8,559 POSTED ENTRY 17 7,829 POSTED ENTRY 18 7,184 POSTED ENTRY 19 6,427 POSTED ENTRY 20 5,803 POSTED ENTRY 21 5,636 POSTED ENTRY 22 5,482 POSTED ENTRY 23 36,928
This page of the report shows the following:
Each count represents two tasks conflicting on the resource. All of these SMP locks are of short duration. Two tasks searching a particular index or data buffer for a read request get share locks and have no contention. If one task might need to update the block, it must run alone. This is true of all the locks as appropriate. All locks are global in nature, that is, only one exists except as follows:
The following explain the event names that can appear in the report:
Incrementing counters in a particular entry in the Accounting buffer.
Accounting system changes across all Accounting tables.
Accounting changes to each specific Accounting table.
Control during add or delete of a sequential or flexpool buffer.
CBS buffer spill to IXX.
Control during get/free memory in the CBS buffer.
Control during interlock detection.
Occurs when using the X_LOG_DELAY MUF startup option which enables the log COMIT delay enhancement. This is a count of times a task doing a transaction-ending command delayed for another task to write the LXX block, but none did within the one second time limit.
Occurs when using the X_LOG_DELAY MUF startup option which enables the log COMIT delay enhancement. This is a count of times a task doing a transaction ending command delayed for another task to write the LXX block and another did, thus saving a possible LXX I/O.
Control of a covered or virtual area during block fetch/store.
A specific data block in memory.
Hash list of data blocks in memory.
The Least Recently Used data chain to read a block not in memory.
Blocks in data area with free space in memory.
Data area space management.
Write pending chain (pipeline) for data.
A DEFRAG SMP lock is used to interact with backwards processing (for example, the LOCBR command). DEFRAG obtains an exclusive SMP lock at the start of each key ID processing. If there are no backward requests for this key ID during the life of the DEFRAG, the lock is simply maintained. If there is a backward request during the process, DEFRAG notes where it is in the DXX (the "lowest" level of the IXX that contains key values and pointers to actual rows) and frees the SMP lock to allow the backward process to run. DEFRAG then reestablishes the lock and rereads its blocks and continues as before. Backwards processing obtains a shared SMP lock.
A specific DXX index block in memory.
Hash list of DXX index blocks in memory.
The Least Recently Used DXX index chain to read a block not in memory.
Write pending chain (pipeline) for index.
Control to get or free an expand buffer.
Control during get/free of entry in index queue.
A specific IXX index block in memory.
Hash list of IXX index blocks in memory.
The Least Recently Used IXX index chain to read a block not in memory.
Control to add, delete, or search the primary exclusive control table.
A specific log block in memory.
The Least Recently Used data chain to read a log block not in memory (by transaction backout).
A task is waiting on access to the Log Area (LXX) control information. This particular condition can occur with all LXX formats, but it occurs more frequently with variable logging. The counts are not within control of the user and should not be a concern, regardless of the count, that is to say, the count is for informational purposes only.
Memory manager control.
Non-SQL miscellaneous other locking.
Share lock to search open table list or additions, exclusive lock to delete entries.
Depth count of a POSTED LIST.
Control of the posted list as required.
Print file (PXX) and console control.
Waits for SMP synchronization with external security.
SQL control of attached tasks.
SQL global locking requirements.
SQL miscellaneous control requirements.
SQL control during starting/stopping a plan.
SQL locking of a task status change.
Control requirements to get/free a TTM block.
SQL control during URT open/close.
STAR storage control.
STAR control task usage.
Control during change in status of task area.
Control to start or stop a new transaction, or to see if a transaction is active.
Lock during user compression routine(s).
Control of the wait list of tasks.
Five of the locks allow a diagnostic startup option (DIAGOPTION) to accumulate the time the task waited. If this has been selected (because of a request by CA Support), the following counts can print. The count reflects the total number of seconds of waiting that occurred.
Time spent waiting for the memory manager lock.
Time spent waiting for the print file (PXX) lock.
Time spent waiting for the RWTSA (task) lock.
Time spent waiting for the timer lock.
Time spent waiting for the wait list lock.
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