Re: wait_event_interruptible_timeout problem

[Gaurav Dhiman <gaurav4lkg@gmail.com>]

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/
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