Re: [RFC][PATCH 7/7] lockdep: spin_lock_nest_lock()

From: Jeremy Fitzhardinge
Date: Mon Aug 04 2008 - 15:27:02 EST


Peter Zijlstra wrote:
3. release the outer lock before releasing the inner locks

Only if you then release the inner locks in the reverse order you took
them - the nested release code (releasing a lock that is not on the top
of the stack) basically pops and pushes all the locks, the push will
fail if the outer lock is released.

OK. I don't actually need to do this, but I was asking for completeness. But to clarify, you only need to do the reverse unlock if you do it after unlocking the outer lock? If you're still holding the outer lock, you can unlock in any order?

but it's not OK to try to use different outer locks for a given inner lock.

It doesn't validate this part - as with most lockdep annotations you can
annotate away real deadlocks.

Hm, OK.


J
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