Re: wait_event_interruptible_timeout problem

Gaurav Dhiman
2005-09-14T06:31:04Z

On 9/14/05, Robert Hancock <hancockr@shaw.ca> wrote:
> manomugdha biswas wrote:
> > Hi,
> > I have a kernel module (kernel 2.6) where I have
> > opened multiple tcp connections. when there is no
> > data
> > i want my process to sleep. For that i have added
> > the
> > following code.
> >
> > /* Initialise the wait q head */
> > init_waitqueue_head(&VNICClientWQHead);
> >
> > init_waitqueue_entry(&(currentMap->waitQ), current);
> > add_wait_queue(currentMap->sock->sk->sk_sleep,
> > &(currentMap->waitQ));
> >
> > /* here currentMap is a structure containing tcp
> > conenction info for my module. There is a currentMap
> > for each tcp connection */
> >
> > wait_event_interruptible_timeout(VNICClientWQHead,
> > 0, HZ * 100000);
> >
> > I am not sure about the condition argument, 0.
>
> The condition should be an expression that returns true when whatever
> you are waiting for occurs - in this case when data is available. If you
> put the condition as 0 it will never wake up.

On timeout it will wake up, even if the condition is 0 ..... bu in
this case the time out is too big. Try with small timeout value and
you will see that your process wakes up.

-Gaurav

>
> Also, why the huge timeout? If you just want to sleep forever, use
> regular wait_event_interruptible.
>
> --
> Robert Hancock Saskatoon, SK, Canada
> To email, remove "nospam" from hancockr@nospamshaw.ca
> Home Page: http://www.roberthancock.com/
>
>
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--
- Gaurav
my blog: http://lkdp.blogspot.com/
--