Re: [RFC] [PATCH] Include LRU in page count

Daniel Phillips
2002-09-01T22:23:54Z

On Monday 02 September 2002 00:09, Andrew Morton wrote:
> Daniel Phillips wrote:
> >
> > ...
> > I'm looking at your spinlock_irq now and thinking the _irq part could
> > possibly be avoided. Can you please remind me of the motivation for this -
> > was it originally intended to address the same race we've been working on
> > here?
> >
>
> scalability, mainly. If the CPU holding the lock takes an interrupt,
> all the other CPUs get to spin until the handler completes. I measured
> a 30% reducton in contention from this.
>
> Not a generally justifiable trick, but this is a heavily-used lock.
> All the new games in refill_inactive() are there to minimise the
> interrupt-off time.

Per-cpu lru lists? Your solution is a lot simpler...

--
Daniel