Enhancements to Linux I/O Scheduling
Seetharami Seelam, Rodrigo A. Romero, Patricia J. Teller, William Buros · 2005
The Linux 2.6 release provides four disk I/O schedulers: deadline, anticipatory, noop, and completely fair queuing (CFQ), along with an option to select one of these four at boot time or runtime. The selection is based on a pri-ori knowledge of the workload, file system, and I/O system hardware configuration, among other factors. The anticipatory scheduler (AS) is the default. Although the AS performs well under many situations, we have identi-fied cases, under certain combinations of work-loads, where the AS leads to process starvation. To mitigate this problem, we implemented an extension to the AS (called Cooperative AS or