Messages in this thread | | | Date | Tue, 30 Dec 2008 23:01:10 +0530 | From | Vaidyanathan Srinivasan <> | Subject | Re: [PATCH v7 0/8] Tunable sched_mc_power_savings=n |
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* Balbir Singh <balbir@linux.vnet.ibm.com> [2008-12-30 08:18:19]:
> * MinChan Kim <minchan.kim@gmail.com> [2008-12-30 08:43:58]: > > > Hi, Vaidyanathan. > > It's very late reponse. :( > > > > > Results: > > > -------- > > > > > > Basic functionality of the code has not changed and the power vs > > > performance benefits for kernbench are similar to the ones posted > > > earlier. > > > > > > KERNBENCH Runs: make -j4 on a x86 8 core, dual socket quad core cpu > > > package system > > > > > > SchedMC Run Time Package Idle Energy Power > > > 0 81.68 52.83% 54.71% 1.00x J 1.00y W > > > 1 80.70 36.62% 70.11% 0.95x J 0.96y W > > > 2 74.95 19.53% 85.92% 0.90x J 0.98y W > > > > > > The results are marginally better than the previous version of the > > > patch series which could be within the test variation. > > > > > > Please feel free to test, and let me know your comments and feedback. > > > I will post more experimental results with various benchmarks. > > > > Your result is very interesting. > > level 2 is more fast and efficient of power. > > > > What's major contributor to use less time in level 2? > > I think it's cache bounce is less time than old. > > Is right ? > > > > Yes, correct > > > I want to test SCHED_MC but I don't know what you use to benchmark about power. > > How do I get the data about 'Package, Idle, Energy, Power'? > > > > Note, it is Package Idle (for both packages), it is a x86-64 8 core, > dual socket, quad core box. It is not Package, Idle. > > For Energy and Power you need a means of measuring power like a meter. >
Hi MinChan,
Thank you for your interest in sched_mc power saving feature. As Balbir has mentioned, you will need a power measurement infrastructure like an external power meter.
Laptops have battery discharge rate measurement that is a good approximation for power consumption. But that is not helpful to test sched_mc since we would need a multi-socket multi core system to get power saving benefit from the enhancements.
The 'package idle' information comes from /proc/stat by adding up the idle times from various logical CPUs belonging to a single physical package. All logical CPUs belonging to a single physical package can be identified from /proc/cpuinfo or /sys/devices/system/cpu/cpu<n>/topology/physical_package_id
--Vaidy
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