Hi! I'm using ftrace in order to trace any task or process running. I'm interesting to the context switch tracing. Ok, I've enabled sched_switch and the results are in the trace file. How can I interpretate correctly the results? What does the following mean?
bash-3997 [01] 240.132281: 3997:120:R + 4055:120:R The process 3997 (pid) with priority 120 is runnnig (R), right? At the time 240.132281 the process 4055 wake up and.... What does the R of the process 4055 mean? bash-3997 [01] 240.132284: 3997:120:R ==> 4055:120:R This is a real context witch, I suppose. Why is 3997 still running? I believe that if there's a context switch, like in this case, the process 3997 should sleep and 4055 starts to run. sleep-4055 [01] 240.132371: 4055:120:S ==> 3997:120:R This is the case that I said above, right? bash-3997 [01] 240.132454: 3997:120:R + 4055:120:S 4005 wake up and it goes to sleep, right? sleep-4055 [01] 240.132460: 4055:120: D ==> 3997:120:R What is D? bash-3997 [01] 240.132463: 3997:120:R + 4055:120: D 4005 wakes up and goes in the state.... I don't know The documentation says that the R state is: the process wants to run, may not actually be running. Is it running or not? How can I know if it's running? Help me. Thanks
