Every task queue has an associated set of kstat counters. Examine the output of the following kstat(1M) command:
$ kstat -c taskq module: unix instance: 0 name: ata_nexus_enum_tq class: taskq crtime 53.877907833 executed 0 maxtasks 0 nactive 1 nalloc 0 priority 60 snaptime 258059.249256749 tasks 0 threads 1 totaltime 0 module: unix instance: 0 name: callout_taskq class: taskq crtime 0 executed 13956358 maxtasks 4 nactive 4 nalloc 0 priority 99 snaptime 258059.24981709 tasks 13956358 threads 2 totaltime 120247890619 |
The kstat output shown above includes the following information:
The name of the task queue and its instance number
The number of scheduled (tasks) and executed (executed) tasks
The number of kernel threads processing the task queue (threads) and their priority (priority)
The total time (in nanoseconds) spent processing all the tasks (totaltime)
The following example shows how you can use the kstat command to observe how a counter (number of scheduled tasks) increases over time:
$ kstat -p unix:0:callout_taskq:tasks 1 5 unix:0:callout_taskq:tasks 13994642 unix:0:callout_taskq:tasks 13994711 unix:0:callout_taskq:tasks 13994784 unix:0:callout_taskq:tasks 13994855 unix:0:callout_taskq:tasks 13994926 |