Re: [PATCH 1/4] irq: correct CPUMASKS_OFFSTACK typo -v2

[Ingo Molnar]

* Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Tue, 14 Apr 2009 13:41:55 -0700
> Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> 
> > irq
> 
> Speaking of which, could someone please take a look at
> http://www.gossamer-threads.com/lists/linux/kernel/1060580?do=post_view_threaded#1060580
> ?
[...]

> But try_one_irq() is running tifm_7xx1_isr() with local interrupts 
> enabled, which upsets lockdep.

It doesnt just upset lockdep, it could also cause real lockups. 
Lockdep is just the canary, the lockup is the methane explosion.

> But I suspect that the code as it stands is non-buggy. Unless the 
> interrupt can magically come back to life. In which case any 
> change we make is purely a make-lockdep-shut-up thing.

Hm, i'd suggest we go for the methane leak instead of squashing the 
canary. Which in this case would be try_one_irq() ignoring 
IRQF_DISABLED or so? Affecting (much) more ISRs than just 
tifm_7xx1_isr()?

Thomas?

	Ingo
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