Messages in this thread |  | | | Date | Tue, 23 Mar 2010 21:56:23 +0100 | | From | Dhaval Giani <> | | Subject | Re: [PATCH 0/3] sched: use EDF to throttle RT task groups v2 |
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> > The biggest problem with the four files used in the current implementation > > is that bandwidth assignments should be atomic (because setting all the > > parameters independently can force the system to go through non-feasible > > assignments, and the order to use when assigning runtime and period > > changes depending on the direction of the change). I know this is a > > dangerous question, but I'll try it anyway: are we ready for multi-valued > > cgroup parameters? > > Right, I don't know about multi-valued files, that sounds like its going > to confuse people too. >
True, but after having used the current interface I feel multi-valued files will be better. For an idea, this is how I currently change bandwidth allocated to a group.
(I am ignoring cpu.rt_ prefixes and _us suffixes for the filenames)
Starting state: task_runtime: 100000, task_period: 1000000. runtime=200000, period=1000000 Suppose I want to bring down the periods to 100000, then first I need to change task_runtime to 10000, then the task period, then the runtime and finally the period. If I want to go the opposite way, then first I need to increase the periods and then the runtimes.
But I can also see why one would not want a multi-valued interface, esp when the idea is just to change the runtimes. (though there is a complicated interaction between task_runtime and runtime which I am not sure how to avoid).
IOW, this interface sucks :-). We really need something better and easier to use. (Sorry for no constructive input)
Thanks, Dhaval
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