Re: [patch] preempt-smp.patch, 2.6.9-rc1-bk14

[Ingo Molnar <mingo@elte.hu>]

* Zwane Mwaikambo <zwane@linuxpower.ca> wrote:

> > In addition to the preemption latency problems, the _irq() variants in
> > the above list didnt do any IRQ-enabling while spinning - possibly
> > resulting in excessive irqs-off sections of code!
> 
> I had a patch for this
> http://www.ussg.iu.edu/hypermail/linux/kernel/0405.3/0578.html and it
> has been running for about 3 months now on a heavily used 4 processor
> box.  It's all a matter of whether Andrew is feeling brave ;)

at a quick glance your patch doesnt seem to cover the following locking
primitives: read_lock_irqsave(), read_lock_irq(), write_lock_irqsave,
write_lock_irq(). Also, i think your 2.6.6 patch doesnt apply anymore
because it clashes with your very nice out-of-line spinlocks patch that
went into -BK recently ;)

anyway, the preempt-smp.patch is a complete and systematic solution that
has been tested, measured and traced quite heavily.

	Ingo