lkml.org 
[lkml]   [2002]   [Oct]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: wake_up from interrupt handler
In this code too.. lost-wakeup problem is not solved

if (event_occured)
else
schedule();

what if in check ' if(event_occured) ' goes to 'else'
and before calling schedule() my ISR interrupted this
thread and set the event..

Also Mike told to disable the interrupt before
checking for event... So When to enable interrupts
then ??

--- Arjan van de Ven <arjanv@redhat.com> wrote:
> On Mon, 2002-10-07 at 14:41, Amol Lad wrote:
> > Hi,
> > I have a kernel thread which did
> add_to_wait_queue()
> > to wait for an event.
> > The event for which above thread is waiting occurs
> in
> > an interrupt handler that calls wake_up() to wake
> the
> > above thread.
> > Now I am faced with a 'lost wakeup' problem, in
> which
> > the
> > kernel thread checks whether event occured, he
> finds
> > it to be 'not-occured' but before calling
> > add_to_wait_queue(), interrupt handler detects
> that
> > the event has occured and calls wake_up().
> > My thread sleeps forever.
>
> set_current_state(TASK_INTERRUPTIBLE);
> add_to_wait_queue(...);
> if (even_occured) { ...}
> else
> schedule();
>
> remove_from_wait_queue(..);
> set_current_state(TASK_RUNNABLE);
>
>
> >
>
>

> ATTACHMENT part 2 application/pgp-signature
name=signature.asc



__________________________________________________
Do you Yahoo!?
Faith Hill - Exclusive Performances, Videos & More
http://faith.yahoo.com
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:29    [W:0.071 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site