A method and tangible medium embodying code for allocating resource units of an allocatable resource among a plurality of clients in a computer is described. In the method, resource units are initially distributed among the clients by assigning to each of the clients a nominal share of the allocatable resource. For each client, a current allocation of resource units is determined. A metric is evaluated for each client, the metric being a function both of the nominal share and a usage-based factor, the usage-based factor being a function of a measure of resource units that the client is actively using and a measure of resource units that the client is not actively using. A resource unit can be reclaimed from a client when the metric for that client meets a predetermined criterion.