A computer includes a processor and multiple components directly or indirectly connected to the processor. Each component is coupled to a control device, and is configured to provide resources for one or more application programs running in the computer. The processor, when executing an application program, attaches a tag to an application request, and sends the tag-attached application request to a control device coupled with a component to which the tag-attached application request is directed. The control device receives the tag-attached application request, determines, based on the tag and a resource allocation policy, an amount of resources in the component and instructs the component to allocate the amount of resources and process the application request in accordance with the amount of resources allocated for the application request.