Hi, > TASK_RUNNING does not necessary means that the task is currently running > on a cpu. It means that it is ready to run or running. I haven't used ftrace yet, but from using commercial RTOSs on microcontrollers I had gotten used to the terminology : "RUNNABLE". I think that's a more appropriate way of describing a task that is ready to run, as Frederic put it. Of course, once a task is actually running that doesn't mean that this is the actual currently scheduled & executing task, but at least then it is "running" as opposed to "runnable".. Perhaps all taste ? Terminology can vary a bit. A good example I think is the standard terminology of RTS & CTS as used on a (virtual) serial port. I personally dislike the designation "Request To Send", it is misleading IMO. I would have thought a better designation might have been "Ready To Receive" or some such - it is much more descriptive of the actual system HW and what the SW should do. (IOW, the port is NOT requesting that something is sent to it per se, it is merely *not* in the state where it can't accept data) Just my 2 cents' worth. Best regards, Kris On Thu, 19 Mar 2009 15:22:59 +0100, Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote: > Hi Paolo, > > On Thu, Mar 19, 2009 at 02:35:13PM +0100, Paolo wrote: >> 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? > > > R: TASK_RUNNING > S: TASK_INTERRUPTIBLE > D: TASK_UNINTERRUPTIBLE > > TASK_RUNNING does not necessary means that the task is currently running > on a cpu. It means that it is ready to run or running. > > TASK_INTERRUPTIBLE means that the task is sleeping, waiting for an event > to wake it up. This event can be several things: a wake_up() on a > wait_queue > for example. In this state, a task will be awaken if a signal arrives for > it. > > TASK_UNINTERRUPTIBLE: the same than INTERRUPTIBLE but it will not be awaken > if a signal arrives. > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
