On Sun, 07 Jun 2015, Nicholas Mc Guire wrote:
>
> Hi !
>
> Noticed that in a number of cases - often while(!kthread_should_stop()){ loops
> the call to set_current_state(...) is inside the loop - but e.g. in the below
> case why would that be needed ? schedule() is not changing the state visibly
> for the loop - so what is the point of setting the state inside the loop ?
>
> e.g. net/core/pktgen.c
> /* Wait for kthread_stop */
> while (!kthread_should_stop()) {
> set_current_state(TASK_INTERRUPTIBLE);
> schedule();
> }
>
> from code review it seems to be that this would be equivalent
>
> set_current_state(TASK_INTERRUPTIBLE);
> while (!kthread_should_stop()) {
> schedule();
> }
>
> what did I miss ?
>
rereading __schedule() - state after schedule() is always
TASK_RUNNING - so setting it back to !=TASK_RUNNING would be
needed in the loop - but in the above case I still don't get the point of
flipping the task state between TASK_INTERRUPTIBLE and TASK_RUNNING
the set_current_state(TASK_INTERRUPTIBLE); seems to have no real
effect as at the end of the loop state is TASK_RUNNING in any case
and ntermediately it is in TASK_RUNNING state as well ?
so I still seem to be missing something here...
thx!
hofrat
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