Re: [PATCH] Fix potential deadlock in mthca

From: Ingo Molnar
Date: Mon Aug 14 2006 - 07:12:55 EST


On Fri, 2006-08-11 at 09:15 -0700, Arjan van de Ven wrote:
> Roland Dreier wrote:
> > Here's a long-standing bug that lockdep found very nicely.
> >
> > Ingo/Arjan, can you confirm that the fix looks OK and I am using
> > spin_lock_nested() properly? I couldn't find much documentation or
> > many examples of it, so I'm not positive this is the right way to
> > handle this fix.
> >
>
> looks correct to me;
>
> Acked-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>

looks good to me too.

Acked-by: Ingo Molnar <mingo@xxxxxxx>

btw., we could introduce a new spin-lock op:

spin_lock_double(l1, l2);
...
spin_unlock_double(l1, l2);

because some other code, like kernel/sched.c, fs/dcache.c and
kernel/futex.c uses quite similar locking.

Ingo

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