Messages in this thread | | | Date | Wed, 15 Jun 2016 11:27:24 -0700 | From | Davidlohr Bueso <> | Subject | Re: [RFC PATCH-tip v2 1/6] locking/osq: Make lock/unlock proper acquire/release barrier |
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On Wed, 15 Jun 2016, Peter Zijlstra wrote:
>In any case, its fairly simple to cure, just add >smp_acquire__after_ctrl_dep() at the end. If we bail because >need_resched() we don't need the acquire I think.
I was just considering this for your smp_cond_acquire/smp_cond_load_acquire rework, so yeah I guess an smp_acquire__after_ctrl_dep would be a nice compromise.
However, I was always under the impression that races with node->locked were rather harmless (as indicated in the mentioned commit) -- which is why ->locked are simple load/stores, with the exception of the unqueueing -- but yeah, that's not even paired.
Thanks, Davidlohr
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