Embedded real-time task scheduling method based on fuzzy importance and idle time

Abstract

The invention discloses an embedded real-time task scheduling method based on fuzzy importance and idle time, at regular intervals of sampling time units, the idle time of a task is obtained again according to the current time and the execution time of the task, then an idle time fuzzified set and an importance fuzzified set are obtained by fuzzifying the idle time and the importance of the task, and then according to the obtained two fuzzified sets, whether the task needs to regulate a ready queue to which the task belongs or not is judged, and by regulating the ready queue to which the task belongs, the real-time task scheduling can be realized; and compared with a traditional accurate idle time priority scheduling method, on one hand, the method uses the fuzzy mode to determine the scheduling priority of the task in view of uncertainty and fuzzy property of the running environment and the task importance, and on the other hand, as the task importance is served as a decision factor of the scheduling priority, when the system is overloaded, the method can reduce the deadline miss ratio of important tasks.

Description

technical field [0001] The invention relates to the computer field, in particular to an embedded real-time task scheduling method based on fuzzy importance and idle time. Background technique [0002] Embedded real-time system is the most important application and research direction in the field of computer at present, how to schedule tasks reasonably is the key to the whole embedded application system. The main characteristics of the embedded real-time system are: 1. The tasks in the system are generally periodic tasks, that is, the tasks are executed repeatedly at fixed time intervals; 2. The task scheduling mechanism is usually based on priority-driven, that is, the task with the highest priority is the most Get running first; 3. Each periodic task often corresponds to a deadline, and the system should try its best to satisfy important tasks before the deadline arrives. [0003] Because many embedded real-time systems are in an unattended environment, the running system ...

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Problems solved by technology

[0014] 2) The idle time priority scheduling method is based on the accurate value of task idle time. In fact, due to factors such as the instability of the system operating environment (such as the network communication application environment) and the inaccuracy of timing, the real accuracy of the task is obtained. The idle time of is more difficult and does not conform to the actual situation of the operating environment, so it is not suitable to be described by precise values

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