apparent sleep
Milton Krutt
milton at krutt.org
Mon Mar 23 08:31:51 EDT 2015
Hi.
Following LDD3, I am dealing with wait queues, on a 2.6.10.
My loop is like:
while(enough()){
prepare_to_wait(&queue_head, &queue_entry, TASK_INTERRUPTIBLE);
atomic_set(&flag, 0);
if (!atomic_read(&flag, 0))
schedule();
finish_wait(&queue_head, &queue_entry);
}
My intention is to wake up the process at each loop by issuing CTRL^D.
Here is what happens:
the first time the process yields the processor, it actually sleeps and
I have to give it a CTRL^D in order to put it again in running state;
unfortunately, in the following loops, although it calls the schedule()
function, it magically regains the processor putting hisself in a running
state (since it runs, I guess the state is a running one).
In a few words, the while loop has thousands of iterations, but CTRL^D is
needed only during the first one.
Thank you all
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