Methods and apparatus for ensuring quality of service in an operating system

A method of ensuring a particular quality of service for an application in a computer system, the method comprising the steps of:

• utilizing an application programming interface of an operating system to establish one or more quality of service guarantees that correspond to a reference to an object;
• and
• providing a particular quality of service to a request in accordance with the one or more quality of service guarantees that correspond to one or more object references used in the request;
• wherein the quality of service guarantees comprise resource reservations, each specifying a portion of a resource set aside for exclusive use by one or more processes;
• wherein the resource reservations are organized hierarchically such that each resource reservation r may have at most one parent and one or more siblings and children, and associated with r is a weight that specifies how r shares the resources of r's parent with r's siblings;
• and
• wherein associated with each resource reservation r is a minimum amount of resources that r receives from its parent p, such that the minimum amount of resources associated with p is at least equal to the sum of the minimum amount of resources associated with each of p's children.

A method of ensuring a particular quality of service for an application in a computer system, the comprising the steps of:

• utilizing an application programming interface of an operating system to establish one or more quality of service guarantees that correspond to a reference to an object;
• and
• providing a particular quality of service to a request in accordance with the one or more quality of service guarantees that correspond to one or more object reference used in the request;
• wherein the quality of service guarantees comprise resource reservations, each specifying a portion of a resource set aside for exclusive use by one or more processes;
• wherein the resource reservations are organized hierarchically such that each resource reservation r may have at most one parent and or more siblings and children, and associated with r is a weight that specifies how r shares the resources of r's parent with r's siblings;
• wherein the application programming interface of the operating system represents a resource reservation as a directory in a hierarchical file system;
• and
• wherein the directory contains one or more files specifying the minimum amount of resource and the weight of the represented resource reservation.

A method of ensuring a particular quality of service for an application in a computer system, the method comprising the steps of:

• utilizing an application programming interface of an operating system to establish one or more quality of service guarantees that correspond to a reference to an object;
• and
• providing a particular quality of service to a request in accordance with the one or more quality of service guarantees that correspond to one or more object reference used in the request;
• wherein the quality of service guarantees comprise resource reservations, each specifying a portion of a resource set aside for exclusive use by one or more processes;
• wherein the resource reservations are organized hierarchically such that each resource reservation r may have at most one parent and one or more sibling and children, and associated with r is a weight that specifies how r shares the resource of r's parent with r's sibling;
• wherein the application programming interface of the operating system represents a resource reservation as a directory in a hierarchical file system;
• and
• wherein if the directory represents an internal reservation r, it contains a first file that when activated creates a subdirectory that represents an additional internal reservation that is a child of r, and second file that when activated creates an additional queue that is a child of r.

A method of ensuring a particular quality of service for an application in a computer system, the method comprising the steps of:

• utilizing an application programming interface of an operating system to establish one or more quality of service guarantees that correspond to a reference to an object;
• and
• providing a particular quality of service to a request in accordance with the one or more quality of service guarantees that correspond to one or more object references used in the request;
• wherein the quality of service guarantees comprise resource reservations, each specifying a portion of a resource set aside for exclusive use by one or more processes;
• wherein the resource reservations are organized hierarchically such that each resource reservation r may have at most one parent and one or more siblings and children, and associated with r is a weight that specifies how r shares the resources of r's parent with r's siblings;
• wherein the application programming interface of the operating system represents a resource reservation as a directory in a hierarchical file system;
• and
• wherein if the directory represents a queue, it contains a first file that when written to clears the number of requests served and amount of service provided and sets a maximum number of requests and amount of service that may be concurrently waiting in the queue, and which when read from returns the number of requests served and the amount of service provided.

A method of ensuring a particular quality of service for an application in a computer system, the method comprising the steps of:

• utilizing an application programming interface of an operating system to establish one or more quality of service guarantees that correspond to a reference to an object;
• and
• providing a particular quality of service to a request in accordance with the one or more quality of service guarantees that correspond to one or more object references used in the request;
• wherein the quality of service guarantees comprise resource reservations, each specifying a portion of a resource set aside for exclusive use by one or more processes;
• wherein the resource reservations are organized hierarchically such that each resource reservation r may have at most one parent and one or more siblings and children, and associated with r is a weight that specifies how r shares the resources of r's parent with r's siblings;
• and
• wherein associated with each process is one root reservation for each resource, such that the process can create, destroy, or modify only resource reservations that descend from the process's root reservations.

An apparatus for ensuring a particular quality of service level for an application in a computer system, the apparatus comprising:

• a processor operative to support an operating system of the computer system, the operating system including a resource reservation application programming interface utilized to establish one or more quality of service guarantees that correspond to a reference to an object, and being further operative to provide a particular quality of service to a request in accordance with the one or more quality of service guarantees that correspond to one or more object references used in the request;
• and
• a memory coupled to the processor and operative to store at least a subset of the quality of service guarantees;
• wherein the resource reservation application programming interface defines a manner in which a parent process running on the operating system is permitted to limit resource reservations used by one or more of its children processes;
• wherein the quality of service guarantees comprise resource reservations each specifying a portion of a resource set aside for exclusive use by one or more processes;
• wherein the resource reservations are organized hierarchically such that each resource reservation r may have at most one parent and one or more siblings and children, and associated with r is a weight that specifies how r shares the resources of r's parent with r's siblings;
• wherein a given one of the resource reservations corresponds to an internal reservation if it is permitted to have children associated therewith in the hierarchy;
• wherein the resource reservation corresponds to a queue if it is not permitted to have children associated therewith in the hierarchy;
• and
• wherein the operating system internally tags each request with a reference to a queue that corresponds to an object reference used in the request.

An article of manufacture comprising a machine-readable medium for storing one or more programs for ensuring a particular quality of service level for an application in a computer system, wherein the one or more programs when executed perform the steps of:

• implementing a resource reservation application programming interface of an operating system used for establishing one or more quality of service guarantees that correspond to a reference to an object;
• and
• providing a particular quality of service to a request in accordance with the one or more quality of service guarantees that correspond to one or more object references used in the request;
• wherein the resource reservation application programming interface defines a manner in which a parent process running on the operating system is permitted to limit resource reservations used by one or more of its children processes;
• wherein the quality of service guarantees comprise resource reservations, each specifying a portion of a resource set aside for exclusive use by one or more processes;
• wherein the resource reservations are organized hierarchically such that each resource reservation r may have at most one parent and one or more siblings and children, and associated with r is a weight that specifies how r shares the resources of r's parent with r's siblings;
• wherein a given one of the resource reservations corresponds to an internal reservation if it is permitted to have children associated therewith in the hierarchy;
• wherein the resource reservation corresponds to a queue if it is not permitted to have children associated therewith in the hierarchy;
• and
• wherein the operating system internally tags each request with a reference to a queue that corresponds to an object reference used in the request.

An apparatus for use in a computer system, the apparatus comprising:

• a resource reservation application programming interface associated with an operating system of the computer system and operative to generate an association between a resource reservation of an application and a reference to a corresponding shared resource of the computer system, wherein the association is utilized to provide a particular quality of service level for the application, and wherein the resource reservation application programming interface defines a manner in which a parent process running on the operating system is permitted to limit resource reservations used by one or more of its children processes;
• wherein the quality of service guarantees comprise resource reservations, each specifying a portion of a resource set aside for exclusive use by one or more processes;
• wherein the resource reservations are organized hierarchically such that each resource reservation r may have at most one parent and one or more siblings and children, and associated with r is a weight that specifies how r shares the resources of r's parent with r's siblings;
• wherein a given one of the resource reservations corresponds to an internal reservation if it is permitted to have children associated therewith in the hierarchy;
• wherein the resource reservation corresponds to a queue if it is not permitted to have children associated therewith in the hierarchy;
• and
• wherein the operating system internally tags each request with a reference to a queue that corresponds to an object reference used in the request.

A method of ensuring a particular quality of service for an application in a computer system, the method comprising the steps of:

• generating, in a resource reservation application programming interface of an operating system of the computer system, an association between a resource reservation and a reference to a corresponding shared resource;
• and
• utilizing the association to provide the particular quality of service for the application;
• wherein the resource reservation application programming interface defines a manner in which a parent process running on the operating system is permitted to limit resource reservations used by one or more of its children processes;
• wherein the quality of service guarantees comprise resource reservations, each specifying a portion of a resource set aside for exclusive use by one or more processes;
• wherein the resource reservations are organized hierarchically such that each resource reservation r may have at most one parent and one or more siblings and children, and associated with r is a weight that specifies how r shares the resources of r's parent with r's siblings;
• wherein a given one of the resource reservations corresponds to an internal reservation if it is permitted to have children associated therewith in the hierarchy;
• wherein the resource reservation corresponds to a queue if it is not permitted to have children associated therewith in the hierarchy;
• and
• wherein the operating system internally tags each request with a reference to a queue that corresponds to an object reference used in the request.