Messages in this thread | | | Date | Thu, 12 May 2005 14:16:50 +0530 | From | Srivatsa Vaddagiri <> | Subject | Re: [RFC] (How to) Let idle CPUs sleep |
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On Wed, May 11, 2005 at 11:03:49AM -0700, Tony Lindgren wrote: > Sorry to jump in late. For embedded stuff we should be able to skip > ticks until something _really_ happens, like an interrupt. > > So we need to be able to skip ticks several seconds at a time. Ticks > should be event driven. For embedded systems option B is really > the only way to go to take advantage of the power savings.
I don't know how sensitive embedded platforms are to load imbalance. If they are not sensitive, then we could let the max time idle cpus are allowed to sleep to be few seconds. That way, idle CPU wakes up once in 3 or 4 seconds to check for imbalance and still be able to save power for those 3/4 seconds that it sleeps.
I guess it is a tradeoff here between the complexity we want to put and the real benefit we get. Its hard for me to get the numbers (since I don't have easy access to the right tools to measure them) to show how much the real benefit is :(
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Thanks and Regards, Srivatsa Vaddagiri, Linux Technology Center, IBM Software Labs, Bangalore, INDIA - 560017 - 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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