Honeywell International Inc.

Honeywell G.m.b.h.

Pamela A Binns

Aaron Raymond Larson

Stephen C Vestal

Ryan Lawrence Roffelsen

Murali Rangarajan

One example is directed to a method of generating a set of schedules for use by a partitioning kernel to execute a plurality of partitions on a plurality of processor cores included in a multi-core processor unit. The method includes determining a duration to execute each of the plurality of partitions without interference and generating a candidate set of schedules using the respective duration for each of the plurality of partitions. The method further includes estimating how much interference occurs for each partition when the partitions are executed on the multi-core processor unit using the candidate set of schedules and generating a final set of schedules by, for at least one of the partitions, scaling the respective duration in order to account for the interference for that partition. The method further includes configuring the multi-core processor unit to use the final set of schedules to control the execution of the partitions using at least two of the cores.

Safe partition scheduling on multi-core processors

A technique for binning aperiodic latency sample data using a data representation called latency band graphs. A fluid flow analysis produces a small, fixed size set of automatically generated bins dependent only on the timeline defined by periodic traffic. The compact number of bins yields a parameterized latency representation suitable for real-time estimation and goodness-of-fit tests.

Real-time estimation of event-driven traffic latency distributions when layered on static schedules

In a multitasking system executing real-time harmonic and dynamic tasks having various priority levels, slack is stolen from timeline and reclaimed slack to enable execution of high priority non-essential tasks on a best efforts basis. Counts of the amount of slack consumed, slack reclaimed, and periodic compute time consumed are maintained by individual priority level and dynamically updated at certain times. Idle time is calculated by priority level. Available slack is calculated, allocated and consumed by rate, with the highest rate first and the lowest last. Slack is made available to tasks in more than one time partition. All slack belongs to a common system-wide pool of slack obtained from any one or more time partitions. Common slack can also be time-shared by static, non-harmonic tasks residing in different time partitions. Also described are a computer system and methods that perform slack scheduling in a time-partitioned system.

Methods and apparatus for sharing slack in a time-partitioned system

In a multitasking system executing real-time harmonic and dynamic tasks having various priority levels, slack is stolen from both timeline and reclaimed slack to enable the execution of high priority non-essential tasks on a best efforts basis. Counts of the amount of slack consumed, slack reclaimed, and periodic compute time consumed are maintained by individual priority level and dynamically updated at certain times. Idle time is calculated by priority level. Available slack is calculated, and slack is allocated and consumed by rate, with the highest rate first and the lowest rate last. Also described are a computer system and various methods that perform slack stealing in a multitasking system in which dynamic tasks can request activation or deactivation at any time.

Method and apparatus for slack stealing with dynamic threads

Methods for modeling real-time periodic and aperiodic task scheduling and message passing within multitask systems. The methods utilize undelayed and single sample delayed message connections among software task objects and hardware objects. Task priorities are assigned inversely with period or deadline, so that tasks with shorter periods or deadlines have higher scheduling priorities. Periods of high-criticality tasks are decomposed into smaller pieces that are sequentially dispatched at higher rates where the initial assignment of priority is inconsistent with task criticality. The methods provide for deterministic communication among periodic processes.

Task scheduling and message passing

A method for scheduling periodic incremental and design to time processes. The algorithm is based on the slack stealer which dynamically determines the remaining slack time after all periodic processes are scheduled utilizing Rate Monotonic Scheduling (RMS). An incremental process determines how much execution time is available after the baseline component has completed and prior to the execution of a process increment. A design to time process determines how much execution time is available before the process begins execution and selects a version which gives the greatest precision in the available time. For both incremental and design to time processes, a minimum amount of time is statically reserved so that an acceptable but suboptimal solution will always be calculated. The solution identifies and proposes solutions for the practical problem of supporting criticalities when scheduling slack and analyzing the run-time overheads.

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North Oaks, MN, United States of America

Pamela A Binns