Re: [2.4.17/18pre] VM and swap - it's really unusable

[Russell King]

On Sat, Jan 12, 2002 at 10:10:55PM -0500, Robert Love wrote:
> It can if we increment the preempt_count in disable_irq_nosync and
> decrement it on enable_irq.

Who says you're going to be enabling IRQs any time soon?  AFAIK, there is
nothing that requires enable_irq to be called after disable_irq_nosync.

In fact, you could well have the following in a driver:

	/* initial shutdown of device */

	disable_irq_nosync(i); /* or disable_irq(i); */

	/* other shutdown stuff */

	free_irq(i, private);

and you would have to audit all drivers to find out if they did this -
this would seriously damage your preempt_count.

-- 
Russell King ([e-mail])                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html