Proportional share resource allocation with reduction of unproductive resource consumption

In a computer that has a system memory resource that is allocatable as machine memory pages that are identified by corresponding machine page numbers (MPNs), a method for allocating units of the resource among a plurality of clients comprising the following steps:

• assigning to each client a share value corresponding to a nominal share of the allocatable resource units that is proportional to its fraction of a total of the shares of all clients;
• for each client, determining a current allocation of resource units;
• for each client, evaluating a metric that is a function both the current allocation and of a usage-based factor that is a function of a first measure of resource units currently allocated to the respective client that that client is actively using and a second measure of resource units currently allocated to the respective client that that client is not actively using;
• in evaluating the metric, assigning greater significance to each unit of the currently allocated resource that the client is not actively using than to each unit of the currently allocated resource that the client is actively using;
• reclaiming and reallocating a resource unit from the client whose metric meets a predetermined criterion;
• in which:
• the clients are virtual machines (VMs) that issue requests for physical pages, which are identified by corresponding physical page numbers (PPNs);
• each VM communicates requests for PPNs via a virtual machine monitor (VMM);
• further including the following steps:
• allocating system memory to the VMs as PPNs;
• mapping PPNs to MPNs within the VMM;
• determining the first and second measures of resource units by evaluating usage by each respective VM of physical pages.

A computer system comprising:

• an allocatable resource that is allocatable in predetermined resource units;
• a plurality of clients sharing the allocatable resource;
• resource management means:
• assigning to each client a share value corresponding to a nominal share of the allocatable resource units that is proportional to its fraction of a total of the shares of all clients;
• for each client, for determining a current allocation of resource units;
• for each client, evaluating a metric that is a function both of the current allocation and of a usage-based factor that is a function of a first measure of resource units currently allocated to the respective client that the client is actively using and a second measure of resource units currently allocated to the respective client that the client is not actively using;
• in evaluating the metric, for assigning greater significance to each unit of the currently allocated resource that the client is not actively using than to each unit of the currently allocated resource that the client is actively using;
• and
• for reclaiming and reallocating a resource unit from the client whose metric meets a predetermined criterion;
• in which:
• the allocatable resource is system memory and the resource units are machine memory pages that are identified by corresponding machine page numbers (MPNs);
• the clients are virtual machines (VMs) that issue requests for physical pages, which are identified by corresponding physical page numbers (PPNs);
• each VM communicates requests for PPNs via a respective virtual machine monitor (VMM);
• the resource management means is further provided for allocating the system memory to the respective VMs as PPNs and for determining the first and second measures of resource units by evaluating usage by each respective client of physical pages;
• and
• each VMM includes mapping means for mapping PPNs to MPNs.