Messages in this thread | | | Date | Fri, 31 Jul 2015 10:39:20 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v3 1/7] locking/pvqspinlock: Unconditional PV kick with _Q_SLOW_VAL |
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On Wed, Jul 22, 2015 at 04:12:36PM -0400, Waiman Long wrote: > The smp_store_release() is not a full barrier. In order to avoid missed > wakeup, we may need to add memory barrier around locked and cpu state > variables adding to complexity. As the chance of spurious wakeup is very > low, it is easier and safer to just do an unconditional kick at unlock > time.
This needs to better spell out the race; my still sleeping brain doesn't want to co-operate and its generally better to spell out these things anyway.
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