Messages in this thread | | | Date | Thu, 29 Mar 2012 11:11:37 +0800 | From | Yong Zhang <> | Subject | Re: Using nested locking for spin_lock_bh |
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On Wed, Mar 28, 2012 at 06:36:39PM +0200, Sven Eckelmann wrote: > Hi, > > I started to run some experimental batman-adv code inside some virtual > machines with different debugging functions enabled. One of them was lockdep. > There we noticed a false positive for a lock class that is actually used in > two different data structures.
Hmm, I think you can initialize the lock class in the two differnent data structures with differnt lock_class_key.
Thanks, Yong
> Therefore, lockdep noticed that there could be > a deadlock for this class in a function that locks the two different data > structures. > > To resolve this problem, I wanted to define two different subclasses and > replace the spin_lock_bh with its nested version. The only problem now is the > absence of spin_lock_bh_nested. I could only find spin_lock_bh and > spin_lock_irqsave_nested. > > Is there another way how this should be done or is there a general problem why > there is no nested support for this incarnation of spin_lock? > > Kind regards, > Sven
-- Only stand for myself
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