Messages in this thread |  | | Subject | Re: [Patch v6 0/7] Introduce Thermal Pressure | From | Thara Gopinath <> | Date | Sat, 11 Jan 2020 10:04:36 -0500 |
| |
On 12/16/2019 09:56 AM, Peter Zijlstra wrote: > On Wed, Dec 11, 2019 at 11:11:41PM -0500, Thara Gopinath wrote: >> Test Results >> >> Hackbench: 1 group , 30000 loops, 10 runs >> Result SD >> (Secs) (% of mean) >> No Thermal Pressure 14.03 2.69% >> Thermal Pressure PELT Algo. Decay : 32 ms 13.29 0.56% >> Thermal Pressure PELT Algo. Decay : 64 ms 12.57 1.56% >> Thermal Pressure PELT Algo. Decay : 128 ms 12.71 1.04% >> Thermal Pressure PELT Algo. Decay : 256 ms 12.29 1.42% >> Thermal Pressure PELT Algo. Decay : 512 ms 12.42 1.15% >> >> Dhrystone Run Time : 20 threads, 3000 MLOOPS >> Result SD >> (Secs) (% of mean) >> No Thermal Pressure 9.452 4.49% >> Thermal Pressure PELT Algo. Decay : 32 ms 8.793 5.30% >> Thermal Pressure PELT Algo. Decay : 64 ms 8.981 5.29% >> Thermal Pressure PELT Algo. Decay : 128 ms 8.647 6.62% >> Thermal Pressure PELT Algo. Decay : 256 ms 8.774 6.45% >> Thermal Pressure PELT Algo. Decay : 512 ms 8.603 5.41% > > What is the conclusion, if any from these results? Clearly thermal > pressuse seems to help, but what window? ISTR we default to 32ms, which > is a wash for drystone, but sub-optimal for hackbench. Hi Peter,
Thanks for the reviews. IMHO, the conclusion is that thermal pressure is beneficial but the decay period to be used depends on the architecture and/or use-cases. Sticking to 32ms should give some improvement but it can be tuned depending on the system.
> > > Anyway, the patches look more or less acceptible, just a bunch of nits, > the biggest being the fact that even if an architecture does not support > this there is still the code and runtime overhead.
I am fixing this and sending out a v7.
>
-- Warm Regards Thara
|  |