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Improving responsiveness of time‐sensitive applications by exploiting dynamic task dependencies
Author(s) -
Cucinotta Tommaso,
Abeni Luca,
Lelli Juri,
Lipari Giuseppe
Publication year - 2018
Publication title -
software: practice and experience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 70
eISSN - 1097-024X
pISSN - 0038-0644
DOI - 10.1002/spe.2557
Subject(s) - computer science , priority inversion , semaphore , posix , distributed computing , system call , scheduling (production processes) , priority inheritance , real time operating system , operating system , inversion (geology) , embedded system , dynamic priority scheduling , rate monotonic scheduling , schedule , operations management , economics , paleontology , structural basin , biology
Summary In this paper, a mechanism is presented for reducing priority inversion in multiprogrammed computing systems. Contrary to well‐known approaches from the literature, this paper tackles cases where the dependency relationships among tasks cannot be known in advance to the operating system. The presented mechanism allows tasks to explicitly declare aforementioned relationships, enabling the operating system scheduler to take advantage of such information and trigger priority inheritance, resulting in reduced priority inversion. We present the prototype implementation of the concept within the Linux kernel in the form of modifications to the standard Portable Operating System Interface (POSIX) condition variable code, along with an extensive evaluation, including a quantitative assessment of the benefits for applications making use of the technique and comprehensive overhead measurements. In addition, we present an associated technique for the theoretical schedulability analysis of a system using the new mechanism, which is useful to determine whether all tasks can meet their deadlines or not, in the specific scenario of tasks interacting only through remote procedure calls and under partitioned scheduling.