Julia Lawall, Inria-Paris
Getting unexpectedly poor performance from your multicore application? Maybe the operating system task scheduler is at fault. The task scheduler is responsible for placing tasks on cores and for selecting which task is allowed to run, at what time, and for how long. As such, the scheduler is a critical component of any operating system and has a major impact on application performance. Still, scheduling decisions are buried deep within the operating system code, making it challenging to diagnose performance problems (or even performance improvements) to determine whether the scheduler is responsible and, if so, in what way. These challenges are compounded for highly multithreaded applications, running on large multicore machines, due to the huge amount of information available.
In this talk, we present some tools that we have developed for visualizing the behavior of the Linux kernel task scheduler, and illustrate how these tools can be used to help diagnose performance problems. The tools presented are freely available at
https://gitlab.inria.fr/schedgraph/schedgraph https://www.usenix.org/conference/srecon24emea/presentation/lawall
