Re: [PATCH 1/2] Allow rwlocks to re-enable interrupts

[Petr Tesarik <ptesarik@suse.cz>]

On Wed, 2008-10-22 at 10:45 +0200, Peter Zijlstra wrote:
> On Wed, 2008-10-22 at 10:34 +0200, Petr Tesarik wrote:
> > c b/kernel/spinlock.c
> > index 29ab207..f769d8a 100644
> > --- a/kernel/spinlock.c
> > +++ b/kernel/spinlock.c
> > @@ -121,7 +121,11 @@ unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
> >  	local_irq_save(flags);
> >  	preempt_disable();
> >  	rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
> > +#ifdef CONFIG_LOCKDEP
> >  	LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
> > +#else
> > +	_raw_read_lock_flags(lock, &flags);
> > +#endif
> >  	return flags;
> >  }
> 
> That should be CONFIG_LOCK_STAT.

Ugh. Fine with me, but is CONFIG_LOCKDEP correct in _spin_lock_irqsave,
or should it also read CONFIG_LOCK_STAT?

> But aside from that, I really don't like this change, I'd rather you'd
> create a LOCK_CONTENDED_FLAGS() that can deal with this.

No problem. I could then also use it for _spin_lock_irqsave, if the
answer to the above question is use CONFIG_LOCK_STAT there as well.

Petr Tesarik