Messages in this thread | | | Date | Tue, 13 Nov 2007 12:59:59 +0530 | From | Balbir Singh <> | Subject | Re: Revert for cgroups CPU accounting subsystem patch |
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Paul Menage wrote: > On Nov 12, 2007 11:00 PM, Balbir Singh <balbir@linux.vnet.ibm.com> wrote: >> Right now, one of the limitations of the CPU controller is that >> the moment you create another control group, the bandwidth gets >> divided by the default number of shares. We can't create groups >> just for monitoring. > > Could we get around this with, say, a flag that always treats a CFS > schedulable entity as having a weight equal to the number of runnable > tasks in it? So CPU bandwidth would be shared between groups in > proportion to the number of runnable tasks, which would distribute the > cycles approximately equivalently to them all being separate > schedulable entities. >
I think it's a good hack, but not sure about the complexity to implement the code. I worry that if the number of tasks increase (say run into thousands for one or more groups and a few groups have just a few tasks), we'll lose out on accuracy.
>> cpu_acct fills this gap. > > Agreed, but not in the right way IMO. >
I think we already have the code, we need to make it more useful and reusable.
-- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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