RE: [PATCH 6/9] mm/z3fold: move decrement of pool->pages_nr into __release_z3fold_page()

[David Laight]

> > Atomic operations aren't magic.
> > Atomic operations are (at best) one slow locked bus cycle.
> > Acquiring a lock is the same.
> > Releasing a lock might be cheaper, but is probably a locked bus cycle.
> >
> > So if you use state_lock to protect pages_nr then you lose an atomic
> > operation for the decrement and gain one (for the unlock) in the increment.
> > That is even or maybe a slight gain.
> > OTOH a 64bit atomic is a PITA on some 32bit systems.
> > (In fact any atomic is a PITA on sparc32.)
> 
> It's actually *stale_lock* and it's very misleading to use it for this.
> I would actually like to keep atomics but I have no problem with
> making it 32-bit for 32-bit systems. Would that work for you guys?

It would be better to rename the lock.

	David

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