A non-intrusive, operating system independent spinlock profiler for embedded multicore systems

Locks are widely used as a synchronization method to guarantee the mutual exclusion for accesses to shared resources in multi-core embedded systems. They have been studied for years to improve performance, fairness, predictability etc. and a variety of lock implementations optimized for different scenarios have been proposed. In practice, applying an appropriate lock type to a specific scenario is usually based on the developer's hypothesis, which could mismatch the actual situation. A wrong lock type applied may result in lower performance and unfairness. Thus, a lock profiling tool is needed to increase the system transparency and guarantee the proper lock usage. In this paper, an operating-system-independent lock profiling approach is proposed as there are many different operating systems in the embedded field. This approach detects lock acquisition and lock releasing using hardware tracing based on hardware-level spinlock characteristics instead of specific libraries or APIs. The spinlocks are identified automatically; lock profiling statistics can be measured and performance-harmful lock behaviors are detected. With this information, the lock usage can be improved by the software developer. A prototype as a Java tool was implemented to conduct hardware tracing and analyze locks inside applications running on the Infineon AURIX microcontrollers.