Re: how to interrupt waiting for a semaphore after a timeout

[Jan Hudec <bulb@ucw.cz>]

On Thu, Oct 02, 2003 at 17:08:16 +0000, Tomaz Beltram wrote:
> So, what do I have to call from my timer function in order that the waiting 
> process becomes signaled? I have tried wake_up_process() but it didn't work.

You DON'T want to do that, because a signal would be delivered to
userland. There were other replies to your original mail that suggested
the right way to go. I only tried to explain whay your original method
could not work.

> Tomaz
> 
> 
> >From: Jan Hudec <bulb@ucw.cz>
> >To: Tomaz Beltram <tomazb@hotmail.com>
> >CC: ruxyz@yahoo.com, kernelnewbies@nl.linux.org
> >Subject: Re: how to interrupt waiting for a semaphore after a timeout
> >Date: Thu, 2 Oct 2003 10:12:08 +0200
> >
> >On Mon, Sep 29, 2003 at 12:02:40 +0000, Tomaz Beltram wrote:
> >> I was looking for a more lightweight solution. I need timed semaphore 
> >down
> >> from within a kernel module. The idea was to substitute down() with
> >> down_interruptible() and check for the return value. I would then 
> >wake_up
> >> the waiting process from another thread after some time. Dynamic timers
> >> seem just perfect for this job. Obviously, I am not doing it the right 
> >way,
> >> as the process remains locked.
> >
> >down_interruptible means it's interruptible with SIGNAL, so it returns
> >only if signal_pending().
> >
> >-------------------------------------------------------------------------------
> >						 Jan 'Bulb' Hudec 
> >						 <bulb@ucw.cz>
> 
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-------------------------------------------------------------------------------
						 Jan 'Bulb' Hudec <bulb@ucw.cz>
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