ACK: [SRU U/L/K/J] Adjust balanced governor for Sappire Rapids

[Tim Gardner]

On 3/10/23 3:53 AM, Stefan Bader wrote:
> BugLink: https://bugs.launchpad.net/bugs/2008519
> 
> The goal is to adjust the behavior of the balanced governor for certain Xeon
> CPUs (those are CPUs rather seen in servers so there should be no impact on
> laptop users). While the initial request was Jammy/5.15 only we should do
> this to Kinetic and Lunar as well so the experience is the same regardless of
> release.
> 
> == Fix ==
> This picks one change from v6.3-rc1 which tweaks the intel_idle driver for a
> specific CPU model. For Jammy/5.15 this requires one additional change
> which introduces the EPP tweak for Alderlake.
> 
> == Regression Potential ==
> The change modifies how quickly CPUs scale up (and probably down) depending on
> workload. Power usage unlikely is of that much concern in server space. Maybe
> increased heat would be observed.
> For Jammy there is the additional risk of havind a different power usage
> on Alderlake which is a Laptop CPU. However that change is part of v5.17
> and thus would already be in effect with current 22.04 HWE.
> 
> 
> Srinivas Pandruvada (1):
>    cpufreq: intel_pstate: Adjust balance_performance EPP for Sapphire
>      Rapids
> 
>   drivers/cpufreq/intel_pstate.c | 1 +
>   1 file changed, 1 insertion(+)
> 
Acked-by: Tim Gardner <tim.gardner at canonical.com>
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Tim Gardner
Canonical, Inc