Hello Tobias, On Sun, Feb 12, 2017 at 7:15 PM, Tobias FItschen <tobias.fitschen@xxxxxxxxxxxxxxxxxxx> wrote: > Hello people, > > I have a question regarding workqueues. I know it's possible to sleep in > workqueue routines. Does that mean I can use: What it means is that you are safe to use any sub routines which may sleep or which will sleep. > > 1. "set_current_state(TASK_INTERRUPTIBLE);" get the the task with > "current" and pass it to a other task and then call "schedule();" in a > workqueue routine and at a different place (perhaps another workqueue > routine) use wake_up_process(task)" ? > > 2. initialize completions in a workqueue routine and call complete() in > a different workqueue routine? > > I tried it in a simple example setup and both worked. I just want to completion variables are written to hide the complexity of using set_current_state and related functions to make a thread sleep. It basically enables driver authors to reuse the same code for sleep/wake. At the heart of it, its all the same. My recommendation is to use completion. > make sure that was not just by accident. As I understand it a work item > is executed on a worker, which is a unique process, but I also know that > there are exceptions, e.g. I can not copy to or from user space in a > workqueue routine. Also I don't know if a worker "sticks" with the > current work item until it is completed or can execute multiple work > items at the "same" time. Yes a kworker sticks with current work item until it is completed. If a work item currently executed by a worker met with a sleep, another kworkers are used to process the other pending work items. Regards, Arun > > 3. In case completions and schedule()/wakeup() work, I would also like > to know, which has the better performance. > > Thanks a lot already! > > Tobias > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
