Title
The Linux scheduler: a decade of wasted cores.
Abstract
As a central part of resource management, the OS thread scheduler must maintain the following, simple, invariant: make sure that ready threads are scheduled on available cores. As simple as it may seem, we found that this invariant is often broken in Linux. Cores may stay idle for seconds while ready threads are waiting in runqueues. In our experiments, these performance bugs caused many-fold performance degradation for synchronization-heavy scientific applications, 13% higher latency for kernel make, and a 14-23% decrease in TPC-H throughput for a widely used commercial database. The main contribution of this work is the discovery and analysis of these bugs and providing the fixes. Conventional testing techniques and debugging tools are ineffective at confirming or understanding this kind of bugs, because their symptoms are often evasive. To drive our investigation, we built new tools that check for violation of the invariant online and visualize scheduling activity. They are simple, easily portable across kernel versions, and run with a negligible overhead. We believe that making these tools part of the kernel developers' tool belt can help keep this type of bug at bay.
Year
DOI
Venue
2016
10.1145/2901318.2901326
EuroSys
Field
DocType
Citations 
Kernel (linear algebra),Resource management,Scheduler activations,Computer science,Scheduling (computing),Latency (engineering),Thread (computing),Real-time computing,Throughput,Operating system,Embedded system,Debugging
Conference
24
PageRank 
References 
Authors
0.97
23
6
Name
Order
Citations
PageRank
Jean-Pierre Lozi11117.13
Baptiste Lepers224010.42
Justin R. Funston31525.42
Fabien Gaud41555.49
Vivien Quéma5100846.07
Alexandra Fedorova6118461.05