In an embodiment, in response to a request from a producer thread to set a bit in a global bitmap, a nodal lock is obtained on a nodal bitmap at a node at which the producer thread executes. A determination is made whether a corresponding bit in a pending clear bitmap in the nodal bitmap indicates that a clear of the bit in the global bitmap is pending. If the corresponding bit in the pending clear bitmap in the nodal bitmap indicates that a clear of the bit in the global bitmap is pending, the corresponding bit in the pending clear bitmap is cleared. If the corresponding bit in the pending clear bitmap in the nodal bitmap indicates that the clear of the bit in the global bitmap is not pending, a corresponding bit in a pending set bitmap in the nodal bitmap is set.