On Fri, May 25, 2007 at 10:14:58AM -0700, Li, Tong N wrote: > Nice work, Vatsa. When I wrote the DWRR algorithm, I flattened the > hierarchies into one level, so maybe that approach can be applied to > your code as well. What I did is to maintain task and task group weights > and reservations separately from the scheduler, while the scheduler only > sees one system-wide weight per task and does not concern about which > group a task is in. The key here is the system-wide weight of each task > should represent an equivalent share to the share represented by the > group hierarchies. To do this, the scheduler looks up the task and group > weights/reservations it maintains, and dynamically computes the > system-wide weight *only* when it need a weight for a given task while > scheduling. The on-demand weight computation makes sure the cost is > small (constant time). The computation itself can be seen from an > example: assume we have a group of two tasks and the group's total share > is represented by a weight of 10. Inside the group, let's say the two > tasks, P1 and P2, have weights 1 and 2. Then the system-wide weight for > P1 is 10/3 and the weight for P2 is 20/3. In essence, this flattens > weights into one level without changing the shares they represent.
What do these task weights control? Timeslice primarily? If so, I am not sure how well it can co-exist with cfs then (unless you are planning to replace cfs with a equally good interactive/fair scheduler :) I would be very interested if this weight calculation can be used for smpnice based load balancing purposes too .. -- Regards, vatsa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
