Budget Fair Queuing IO Scheduler
Apr 17, 2008, 09:00 (0 Talkback[s])
Re-Imagining Linux Platforms to Meet the Needs of Cloud Service Providers
"'We are working [on] a new I/O scheduler based on CFQ, aiming
at improved predictability and fairness of the service, while
maintaining the high throughput it already provides,' began Fabio
Checconi, announcing the BFQ I/O scheduler. 'The Budget Fair
Queueing (BFQ) scheduler turns the CFQ Round-Robin scheduling
policy of time slices into a fair queuing scheduling of sector
budgets,' he continued, 'more precisely, each task is assigned a
budget measured in number of sectors instead of amount of time, and
budgets are scheduled using a slightly modified version of WF2Q+.
The budget assigned to each task varies over time as a function of
its behaviour. However, one can set the maximum value of the budget
that BFQ can assign to any task...'"