These columns identify how many processes are blocked for each possible reason. These columns total (minus ProcPendDBLock) approximately ProcBlocked, since we can only be blocked on one blocking type at a time.
In analyzing resource usage, a distinction should be made between the following two kinds of process blocks:
- Block involves a process that is logically idle, waiting to receive work on its primary mailbox, or for a timer to elapse. This block does not affect throughput.
- Block involves a process that has work to do but is being prevented from proceeding by some circumstance like a segment lock or flow control. This kind of block does affect throughput.
The first kind of block is represented by column ProcPendNetRead; the second kind is represented by the remaining columns described here.
| Column Name | Mode | Description | Data Type |
|---|---|---|---|
| ProcPendDBLock | track | Number of processes blocked pending database locks. | FLOAT |
| ProcPendFsgLock | track | Number of processes blocked pending an FSG lock. | FLOAT |
| ProcPendFsgRead | track | Number of processes blocked pending a File Segment (FSG) read from disk. | FLOAT |
| ProcPendFsgWrite | track | Number of processes blocked pending an FSG write to disk. | FLOAT |
| ProcPendMemAlloc | track | Number of processes blocked pending memory allocations. | FLOAT |
| ProcPendMisc | track | Number of processes blocked pending miscellaneous events. | FLOAT |
| ProcPendMonitor | track | Number of processes blocked pending a user monitor. | FLOAT |
| ProcPendMonResume | track | Number of processes blocked pending a user monitor resume from a yield. | FLOAT |
| ProcPendNetRead | track | Number of processes blocked pending non-step work, that is, the number of processes blocked on any mailbox other than the work mailbox. Non-step work is anticipated work the process spawned off and is now waiting for some type of response from the spawned process or processes. Non-step work is not unanticipated work such as a new work request sent when a user initiates a request from the host.
|
FLOAT |
| ProcPendNetThrottle | track | Number of processes blocked pending delivery of outstanding outgoing messages. | FLOAT |
| ProcPendQnl | track | Number of processes blocked pending a TSKQNL lock. | FLOAT |
| ProcPendSegLock | track | Number of processes blocked pending a segment lock. | FLOAT |