On Fri, Apr 05, 2019 at 03:21:05PM -0400, Waiman Long wrote: > Because of writer lock stealing, it is possible that a constant > stream of incoming writers will cause a waiting writer or reader to > wait indefinitely leading to lock starvation. > > The mutex code has a lock handoff mechanism to prevent lock starvation. > This patch implements a similar lock handoff mechanism to disable > lock stealing and force lock handoff to the first waiter in the queue > after at least a 5ms waiting period. The waiting period is used to > avoid discouraging lock stealing too much to affect performance.
So the mutex code doesn't have that timeout, it foces the handoff if the top waiter fails to acquire. I don't find the above sufficiently justifies the additional complexity. What were the numbers with the simple scheme vs this etc..
