stable 6.6: commit "sched/cpufreq: Rework schedutil governor performance estimation' causes a regression
Hi,
We are observing a performance regression on one of our arm64 boards. We tracked it down to the linux-6.6.y commit ada8d7fa0ad4 ("sched/cpufreq: Rework schedutil governor performance estimation").
UI speedometer benchmark: w/commit: 395 +/-38 w/o commit: 439 +/-14
On 11/20/25 04:45, Sergey Senozhatsky wrote:
Hi,
We are observing a performance regression on one of our arm64 boards. We tracked it down to the linux-6.6.y commit ada8d7fa0ad4 ("sched/cpufreq: Rework schedutil governor performance estimation").
UI speedometer benchmark: w/commit: 395 +/-38 w/o commit: 439 +/-14
Hi Sergey, Would be nice to get some details. What board? What do the OPPs look like? Does this system use uclamp during the benchmark? How? Given how large the stddev given by speedometer (version 3?) itself is, can we get the stats of a few runs? Maybe traces of cpu_frequency for both w/ and w/o?
On Thu, 20 Nov 2025 at 05:45, Sergey Senozhatsky senozhatsky@chromium.org wrote:
Hi,
We are observing a performance regression on one of our arm64 boards. We tracked it down to the linux-6.6.y commit ada8d7fa0ad4 ("sched/cpufreq: Rework schedutil governor performance estimation").
Do you have the fix ? https://lore.kernel.org/all/170539970061.398.16662091173685476681.tip-bot2@t...
And do you have more details to share?
UI speedometer benchmark: w/commit: 395 +/-38 w/o commit: 439 +/-14
linux-stable-mirror@lists.linaro.org
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Christian Loehle -
Sergey Senozhatsky -
Vincent Guittot