Deadline Task Scheduling for Mitigating the CPU Performance Interference in Android Systems

Jeongwoong Lee, Taehyung Lee, Young Ik Eom

http://doi.org/10.5626/JOK.2020.47.1.11

In the Android Linux kernel, most of the tasks are expected to run fairly, and so, there can be delays in processing time-sensitive applications. In particular, since the user may feel inconveniences when the delay occurs in media data processing or biometrics processing such as fingerprint recognition, the tasks requiring completion within a given time should be considered as deadline tasks. However, using the deadline scheduler in current Android systems can cause two problems. First, as deadline tasks come to the system and are executed, the CPU energy consumption can be increased. Second, the high priority of the deadline tasks can cause performance degradation of the normal tasks. To mitigate these problems, this paper proposes a method of scheduling deadline tasks on Android systems, which reduces the performance impact on normal tasks, while trying to minimize energy consumption. Our evaluation on the CPU benchmark shows that the proposed method improves the CPU performance by about 10% compared with the conventional deadline scheduler, but does not increase power consumption by effectively utilizing CPU frequency.