The data section of SMF record type 79 is unique to each report. It is composed of one or more data sections called relocate blocks and, possibly, one data control section. A relocate block is the portion of the SMF record that contains the data for one report data line. A record for a row report has one relocate block. A record for a table report has multiple relocate blocks; for example, the SMF record for the address space state data report includes one relocate block for each address space included in the report. When your SMF record has multiple relocate blocks and you are gathering data that applies to all of them, you can, instead of reporting the data in each relocate block, place this common data in a data control section, as described later under "Data Control Section".
The format of the data in the relocate block depends on the report you are generating. You set the format that best meets your needs. When you are generating a table report, the SMF record consists of multiple relocate blocks, and each relocate block must have the same length.
When you add a menu item to ERBFMENU or an option to ERBBMENU, the entry that describes the new report must include a field that specifies the length of the relocate block, the maximum number of possible relocate blocks, and the length of the data control section. For information on how to add an entry to ERBFMENU or ERBBMENU, see Using the PICTURE macro. To determine the storage to allocate, RMF™ multiplies the length of the relocate block by the maximum number of relocate blocks and adds this value to the length of the data control section and the common section. The result of this computation is the maximum possible length of the SMF record, and RMF allocates a buffer for the record that is equal in size to the maximum length.
To determine the actual length of the SMF record, the data gatherer must complete the fields in the individual header extension section that describe the offset, length, and number of data sections and the data control sections. After the data gatherer has completed its processing and returned control, RMF uses these values to determine the length of the SMF record to be written to the SMF data set, a calculation that is performed only when the RECORD option is in effect for a background session. Note that the value your routine sets in SMF79ASL and the value specified for RBLEN in the PICTURE macro for the report should be identical.
Other fields in the common section that the data gather completes are R79GTOD and SMF79STY. R79GTOD must contain a packed decimal value that indicates the time when the data gatherer was invoked, in the form 0hhmmssF, where F is the sign. SMF79STY can contain the subtype number of the SMF record that you are creating. You use this number as a unique identifier for each record subtype that you create; no subtype number should be less than 1000.
The maximum length of an SMF record is 32,756 bytes; any records that exceed this length are truncated before they are written to the SMF data set. Truncation, which can occur only during a background session when the RECORD option is in effect, occurs at the last relocate block boundary within the maximum length. When truncation occurs, RMF adjusts the field indicating the capacity of the buffer (SMF79ASN) to indicate the actual number of relocate blocks in the record. If no truncation occurs, RMF leaves SMF79ASN unchanged.