Messages in this thread |  | | | Date | Tue, 30 Dec 2008 12:14:32 +0530 | | From | Balbir Singh <> | | Subject | Re: [PATCH v7 0/8] Tunable sched_mc_power_savings=n |
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* Ingo Molnar <mingo@elte.hu> [2008-12-30 07:21:39]:
> > * Balbir Singh <balbir@linux.vnet.ibm.com> wrote: > > > > > 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 > > > > 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 > > yes, i too noticed that runtime improved so dramatically: +7.5% on > kernbench is a _very_ big deal. >
Yes, it is, I think one way to identify it on the x86 box would be to use the performance counter patches, I'll see it I can get it working.
> So i wanted to ask you to re-test whether this speedup is reproducible, > and if yes, please check a few other workloads (for example sysbench on > postgresql / mysqld) and send a patch that changes the > sched_mc_power_savings default to POWERSAVINGS_BALANCE_WAKEUP (2). >
We'll do that, Vaidyanathan is on vacation and will be back in the first week of January. We'll revert back with more tests and results. From code review, it would seem that the benefits are going to be workload specific, but results would show for certain.
> Sidenote, _please_ fix your mail client to not mess up the Cc: list via: >
Thanks, mutt has this turned on by default, I am turning it off and hope that followup-to goes away.
-- Balbir
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