Re: [PATCH] Fix x86_64 _spin_lock_irqsave()

[Suleiman Souhlal]

Andi Kleen wrote:
> Edward Falk <efalk@xxxxxxxxxx> writes:
>
>
> > Add spin_lock_string_flags and _raw_spin_lock_flags() to
> > asm-x86_64/spinlock.h so that _spin_lock_irqsave() has the same
> > semantics on x86_64 as it does on i386 and does *not* have interrupts
> > disabled while it is waiting for the lock.
>
>
> Did it fix anything for you?

I think this was to work around the fact that some buggy drivers try to 
grab spinlocks without disabling interrupts when they should, which 
would cause deadlocks when trying to rendez-vous every cpu via IPIs.

It's a bad idea to spin with interrupts disabled when they could very 
well be enabled, anyway.

-- Suleiman
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