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

Rik van Riel
2002-01-08T21:25:38Z

On 8 Jan 2002, Robert Love wrote:
> On Tue, 2002-01-08 at 16:08, Rik van Riel wrote:
>
> > The preemptible kernel ALSO has to wait for a scheduling point
> > to roll around, since it cannot preempt with spinlocks held.
> >
> > Considering this, I don't see much of an advantage to adding
> > kernel preemption.
>
> It only has to wait if locks are held and then only until the locks are
> dropped. Otherwise it will preempt on the next return from interrupt.

So what exactly _is_ the difference between an explicit
preemption point and a place where we need to explicitly
drop a spinlock ?

>From what I can see, there really isn't a difference.

> Future work would be to look into long-held locks and see what we can
> do.

One thing we could do is download Andrew Morton's patch ;)

Rik
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