apparent sleep

apparent sleep

[Milton Krutt]

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

apparent sleep

[Greg KH]

On Mon, Mar 23, 2015 at 05:31:51AM -0700, Milton Krutt wrote:
> Hi.
> 
> Following LDD3, I am dealing with wait queues, on a 2.6.10.

Please use a modern kernel, 2.6.10 is _very_ old and no one can do
anything about it, and those that could, have long forgotten what was in
it.

good luck,

greg k-h