On 2026.02.10 12:52 Vincent Guittot wrote:
> On Mon, 9 Feb 2026 at 16:47, Peter Zijlstra <peterz@infradead.org> wrote:
>> On Wed, Feb 04, 2026 at 03:45:58PM +0530, K Prateek Nayak wrote:
>
... delete ...

> This patch w/ the patchset on top of tip/sched/core create regressions
> for hackbench (tbench doesn't seem to be impacted) on my dragonboard
> rb5
> All hackbench tests are regressing. Some results below
...
> hackbench 8 group process socket
> 0.650(+/-1%) vs 2.361(+/-8.8%) : -263%
...

Very interesting.
I only know of the Phoronix version of hackbench.
I ran what I believe to be a similar scenario to yours:
10 test runs each (the default is 3):

Kernel 6.19-rc8: 23.228 seconds average, deviation 0.39%
Kernel 6.19-rc8-pz-v2: 85.755 seconds average, deviation 3.33%
269% regression. (very similar to Vicent's results)

System:
Processor: Intel(R) Core(TM) i5-10600K CPU @ 4.10GHz, 6 cores 12 CPUs.
CPU frequency scaling driver: intel_pstate.
CPU frequency scaling governor: powersave.
HWP: enabled.
idle governor teo.