| Date | Fri, 12 Nov 2010 18:42:07 +0100 | From | Tommaso Cucinotta <> | Subject | Re: [RFC][PATCH 02/22] sched: add extended scheduling interface |
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Il 12/11/2010 17:38, Steven Rostedt ha scritto: > A while ago I implemented an EDF scheduler for a client (before working > with Red Hat), and one thing they asked about was having a "soft group", > which was basically: This group is guaranteed X runtime in Y period, but > if the system is idle, let the group run, even if it has exhausted its X > runtime. > > Is this supported? Actually, I know that Dario has an implementation of exactly this feature (and it used to be implemented in our previous scheduler as well, i.e., the old AQuoSA stuff): a per-task flag, when enabled, allows to put temporarily the task into SCHED_OTHER when its budget is exhausted. Therefore, it will be allowed to run for more than its budget but without breaking the temporal isolation with the other SCHED_DEADLINE tasks. Furthermore, it won't starve other SCHED_OTHER tasks, as it will compete with them for the CPU during the budget-exhausted time windows.
T.
-- Tommaso Cucinotta, Computer Engineering PhD, Researcher ReTiS Lab, Scuola Superiore Sant'Anna, Pisa, Italy Tel +39 050 882 024, Fax +39 050 882 003 http://retis.sssup.it/people/tommaso
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