Messages in this thread | | | Subject | Re: [PATCH 1/8] lockdep: fix recursive read lock validation | From | Peter Zijlstra <> | Date | Tue, 29 Apr 2008 19:04:03 +0200 |
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On Tue, 2008-04-29 at 18:29 +0200, Bart Van Assche wrote: > On Tue, Apr 29, 2008 at 6:15 PM, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote: > > > > > Or: whether or not to allow a sequence like "rlock(a); rlock(b); > > > runlock(b); runlock(a); rlock(b); rlock(a);" is something we can > > > choose. We do not have to forbid this sequence -- we can choose > > > whether or not we allow this sequence. > > > > I'm utterly confused now; I never argued that it would get deadlocks; > > and I said I choose to not allow it from a lockdep pov. What else do you > > want? > > So we both agree that the statement in the original e-mail (by Gautham > R Shenoy) is wrong ? The original e-mail stated that obtaining reader > locks in an inconsistent order is wrong.
I think the critical part is:
> It really is invalid when considered against write locks.
Aside from that it just states that inversion of lock order will be treated as invalid - even for read locks.
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