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From: Oliver Neukum <oliver@neukum.name>
To: Thunder from the hill <thunder@lightweight.ods.org>
Subject: Re: question on spinlocks
Date: Mon, 2 Sep 2002 00:33:23 +0200
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       Ralf Baechle <ralf@uni-koblenz.de>, <linux-kernel@vger.kernel.org>
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Am Montag, 2. September 2002 00:09 schrieb Thunder from the hill:
> Hi,
>
> On Mon, 2 Sep 2002, Oliver Neukum wrote:
> > > > No; spin_lock_irqsave/spin_unlock_irqrestore and
> > > > spin_lock/spin_unlock have to be used in matching pairs.
> > >
> > > If it was his least problem! He'll run straight into a "schedule
> > > w/IRQs disabled" bug.
> >
> > OK, how do I drop an irqsave spinlock if I don't have flags?
>
> IMHO you might even ask "How do I start a car when I don't have the
> keys?"

Break off the lock, touch some cables ... ;-)

> You might find a way, but it's not desired. Are you sure you want to
> reschedule in an interrupt handler? If it's none, are you sure you want
> to disable interrupts?

I am not in an interrupt handler. It's not my fault that the scsi layer
calls queuecommand with a spinlock held. But I need to sleep,
I have to get rid of that spinlock's effects. If possible I even want
interrupts to be enabled.

	Regards
		Oliver

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