Min S Lee

US Patent:

8161491, Apr 17, 2012

Filed:

Apr 27, 2010

Appl. No.:

12/768458

Inventors:

Anjur Sundaresan Krishnakumar - Princeton NJ, US
Parameshwaran Krishnan - Basking Ridge NJ, US
Min Lee - Atlanta GA, US
Navjot Singh - Denville NJ, US
Shalini Yajnik - Berkeley Heights NJ, US

Assignee:

Avaya Inc. - Basking Ridge NJ

International Classification:

G06F 9/455
G06F 9/46
G06F 15/173

US Classification:

718105, 718 1, 718103, 709223, 709224, 709226

Abstract:

The present disclosure is based on a multi-core or multi-processor virtualized environment that comprises both time-sensitive and non-time-sensitive tasks. The present disclosure describes techniques that use a plurality of criteria to choose a processing resource that is to execute tasks. The present disclosure further describes techniques to re-schedule queued tasks from one processing resource to another processing resource, based on a number of criteria. Through load balancing techniques, the present invention both (i) favors the processing of soft real-time tasks arising from media servers and applications, and (ii) prevents “starvation” of the non-real-time general computing applications that co-exist with the media applications in a virtualized environment. These techniques, in the aggregate, favor the processing of soft real-time tasks while also reserving resources for non-real-time tasks. These techniques manage multiple processing resources to balance the competing demands of soft real-time tasks and of non-real-time tasks.

US Patent:

8166485, Apr 24, 2012

Filed:

Aug 4, 2010

Appl. No.:

12/849921

Inventors:

Anjur Sundaresan Krishnakumar - Princeton NJ, US
Parameshwaran Krishnan - Basking Ridge NJ, US
Min Lee - Atlanta GA, US
Navjot Singh - Denville NJ, US
Shalini Yajnik - Berkeley Heights NJ, US

Assignee:

Avaya Inc. - Basking Ridge NJ

International Classification:

G06F 9/46
G06F 9/455
G06F 15/173

US Classification:

718104, 718 1, 718105, 709224, 709225, 709226

Abstract:

Methods are disclosed that dynamically improve soft real-time task performance in virtualized computing environments under the management of an enhanced hypervisor comprising a credit scheduler. The enhanced hypervisor analyzes the on-going performance of the domains of interest and of the virtualized data-processing system. Based on the performance metrics disclosed herein, some of the governing parameters of the credit scheduler are adjusted. Adjustments are typically performed cyclically, wherein the performance metrics of an execution cycle are analyzed and, if need be, adjustments are applied in a later execution cycle. In alternative embodiments, some of the analysis and tuning functions are in a separate application that resides outside the hypervisor. The performance metrics disclosed herein include: a “total-time” metric; a “timeslice” metric; a number of “latency” metrics; and a “count” metric. In contrast to prior art, the present invention enables on-going monitoring of a virtualized data-processing system accompanied by dynamic adjustments based on objective metrics.

US Patent:

8245234, Aug 14, 2012

Filed:

Jan 13, 2010

Appl. No.:

12/686719

Inventors:

Anjur Sundaresan Krishnakumar - Princeton NJ, US
Parameshwaran Krishnan - Basking Ridge NJ, US
Min Lee - Atlanta GA, US
Navjot Singh - Denville NJ, US
Shalini Yajnik - Berkeley Heights NJ, US

Assignee:

Avaya Inc. - Basking Ridge NJ

International Classification:

G06F 9/46

US Classification:

718103, 718104

Abstract:

A method for scheduling the execution of tasks on a processor is disclosed. The purpose of the method is in part to serve the special needs of soft real-time tasks, which are time-sensitive. A parameter Δ is an estimate of the amount of time required to execute the task. Another parameter Γ is the maximum amount of time that the task is to spend in a queue before being executed. In the illustrative embodiment, the preferred wait time Γfor a newly-arrived task Tis expected to be met though the insertion of the newly-arrived task Tinto a position k in a queue such that position k respects the task's preferred wait time Γin light of the expected execution times of the other tasks already in the queue.

US Patent:

8499303, Jul 30, 2013

Filed:

Apr 19, 2012

Appl. No.:

13/450520

Inventors:

Anjur Sundaresan Krishnakumar - Princeton NJ, US
Parameshwaran Krishnan - Basking Ridge NJ, US
Min Lee - Atlanta GA, US
Navjot Singh - Denville NJ, US
Shalini Yajnik - Berkeley Heights NJ, US

Assignee:

Avaya Inc. - Basking Ridge NJ

International Classification:

G06F 9/46
G06F 15/173

US Classification:

718104, 718102, 718105, 709224, 709226

Abstract:

Methods to dynamically improve soft real-time task performance in virtualized computing environments under the management of an enhanced hypervisor comprising a credit scheduler. The enhanced hypervisor analyzes the on-going performance of the domains of interest and of the virtualized data-processing system. Based on the performance metrics disclosed herein, some of the governing parameters of the credit scheduler are adjusted. Adjustments are typically performed cyclically, wherein the performance metrics of an execution cycle are analyzed and adjustments may be applied in a later execution cycle. In alternative embodiments, some of the analysis and tuning functions are in a separate application that resides outside the hypervisor. The performance metrics disclosed herein include: a “total-time” metric; a “timeslice” metric; a number of “latency” metrics; and a “count” metric. In contrast to prior art, the present invention enables on-going monitoring of a virtualized data-processing system accompanied by dynamic adjustments based on objective metrics.