Messages in this thread | | | Date | Fri, 26 Apr 2013 17:40:27 +0200 | Subject | Re: [RFC PATCH v4 00/14] sched: packing small tasks | From | Vincent Guittot <> |
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On 26 April 2013 17:00, Arjan van de Ven <arjan@linux.intel.com> wrote: > On 4/25/2013 10:23 AM, Vincent Guittot wrote: >> >> Hi, >> >> This patchset takes advantage of the new per-task load tracking that is >> available in the kernel for packing the tasks in as few as possible >> CPU/Cluster/Core. It has got 2 packing modes: >> -The 1st mode packs the small tasks when the system is not too busy. The >> main >> goal is to reduce the power consumption in the low system load use cases >> by >> minimizing the number of power domain that are enabled but it also keeps >> the >> default behavior which is performance oriented. >> -The 2nd mode packs all tasks in as few as possible power domains in order >> to >> improve the power consumption of the system but at the cost of possible >> performance decrease because of the increase of the rate of ressources >> sharing >> compared to the default mode. > > > > so I got to ask the hard question; what percentage of system level (not just > cpu level) > power consumption gain can you measure (pick your favorite workload)... >
I haven't system level figures for my patches but only for the cpu subsystem. If we use the MP3 results in the back of my mail, they show an improvement of 37 % (113/178) for the CPU subsystem of the platform. If we assume that the CPU subsystem contributes 25% of an embedded system power consumption (this can vary across platform depending of the use of HW accelerator but it should be a almost fair percentage), the patch can impact the power consumption on up to 9%.
> on x86 (even on the low power stuff) I expect this to be very far into the > noise > (since we have per core power gates, and power transitions are pretty fast) > > you have some numbers in the back of your mail, but it's hard for me to get > a conclusion out of > that (they either measure only cpu power, or are just vague in general) > > > -- > 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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