Re: stable: commit "cpuidle: menu: Avoid discarding useful information" causes regressions

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Oct 14, 2025 at 04:43:43PM +0900, Sergey Senozhatsky wrote:
> Hello,
> 
> We are observing performance regressions (cpu usage, power
> consumption, dropped frames in video playback test, etc.)
> after updating to recent stable kernels.  We tracked it down
> to commit 3cd2aa93674e in linux-6.1.y and commit 3cd2aa93674
> in linux-6.6.y ("cpuidle: menu: Avoid discarding useful information",
> upstream commit 85975daeaa4).
> 
> Upstream fixup fa3fa55de0d ("cpuidle: governors: menu: Avoid using
> invalid recent intervals data") doesn't address the problems we are
> observing.  Revert seems to be bringing performance metrics back to
> pre-regression levels.
> 

For some reason that commit was not added to the 6.1 releases, sorry
about that.  Can you submit a working/tested backport so we can queue it
up after the next round of releases in a few days?

thanks,

greg k-h