Messages in this thread | | | Date | Wed, 28 Sep 2022 19:09:40 +0200 | Subject | Re: [RFC PATCH 0/1] sched/pelt: Change PELT halflife at runtime | From | Dietmar Eggemann <> |
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+ Kajetan Puchalski <kajetan.puchalski@arm.com>
On 20/09/2022 16:07, Jian-Min Liu wrote: > > Update some test data in android phone to support switching PELT HL > is helpful functionality. > > We switch runtime PELT HL during runtime by difference scenario e.g. > pelt8 in playing game, pelt32 in camera video. Support runntime > switching PELT HL is flexible for different workloads. > > the below table show performance & power data points: > > --------------------------------------------------------------------- > --| | PELT > halflife | > | |----------------------------------------------| > | | 32 | 16 | 8 | > | |----------------------------------------------| > | | avg min avg | avg min avg | avg min avg| > | Scenarios | fps fps pwr | fps fps pwr | fps fps pwr| > |---------------------------------------------------------------------| > | HOK game 60fps | 100 100 100 | 105 *134* 102 | 104 *152* 106| > | HOK game 90fps | 100 100 100 | 101 *114* 101 | 103 *129* 105| > | HOK game 120fps | 100 100 100 | 102 *124* 102 | 105 *134* 105| > | FHD video rec. 60fps | 100 100 100 | n/a n/a n/a | 100 100 103| > | Camera snapshot | 100 100 100 | n/a n/a n/a | 100 100 102| > ----------------------------------------------------------------------- > > HOK ... Honour Of Kings, Video game > FHD ... Full High Definition > fps ... frame per second > pwr ... power consumption > > table values are in %
I assume that you are specifically interested in those higher min fps numbers which can be achieved with a tolerable energy consumption increase when running the game with 16ms or even 8ms PELT halflife.
We see a similar effect when running the UI performance benchmark Jankbench.
So you need this runtime-switchable PELT multiplier. Would this sched feature interface:
https://lkml.kernel.org/r/YwyOzgbbUbB+JmSH@hirez.programming.kicks-ass.net
be sufficient for you? People don't like to support `changing PELT halflife` via an official sysctl.
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