A realtime preemption overview
Posted Aug 18, 2005 7:35 UTC (Thu) by goaty
Parent article: A realtime preemption overview
Concerning the multiple reader problem, if you'll forgive my naivety, isn't it sufficient just to upgrade one reader at a time? This is assuming that upgrades are transitive, so if the upgraded reader is waiting on an un-upgraded reader, the upgrade will be passed down the chain. Assuming each lock has a linked-list of readers, this seems straightforward. Obviously once a reader releases the lock, we need to give the next reader an upgrade, as long as there are readers remaining. This should limit the scheduler overhead to be proportional to the number of locks, rather than the number of readers.
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