Messages in this thread | | | Date | Wed, 27 Mar 2019 11:45:44 +0800 | From | Herbert Xu <> | Subject | Re: [PATCH 3/4] rhashtable: use bit_spin_locks to protect hash bucket. |
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On Wed, Mar 27, 2019 at 09:35:18AM +1100, NeilBrown wrote: > > The bit_spin_unlock(), which I am avoiding as unnecessary, would have > provided release semantics. > i.e. any write by this CPU that happened before the releasing write > will be visible to other CPUs before (or when) they see the result of > the releasing write. > This is (as I understand it) exactly that rcu_assign_pointer() promises > - even before acquire semantics were added as Paul just reported. > > So yes, I am sure (surer now that I've walked through it carefully).
Given that rcu_assign_pointer now does a store release it should indeed be safe. Thanks! -- Email: Herbert Xu <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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