Christian Loehle
4499143980
The logic for recent intercepts didn't work, there is an underflow
of the 'recent' value that can be observed during boot already, which
teo usually doesn't recover from, making the entire logic pointless.
Furthermore the recent intercepts also were never reset, thus not
actually being very 'recent'.
Having underflowed 'recent' values lead to teo always acting as if
we were in a scenario were expected sleep length based on timers is
too high and it therefore unnecessarily selecting shallower states.
Experiments show that the remaining 'intercept' logic is enough to
quickly react to scenarios in which teo cannot rely on the timer
expected sleep length.
See also here:
https://lore.kernel.org/lkml/0ce2d536-1125-4df8-9a5b-0d5e389cd8af@arm.com/
Fixes: 77577558f2 ("cpuidle: teo: Rework most recent idle duration values treatment")
Link: https://patch.msgid.link/20240628095955.34096-3-christian.loehle@arm.com
Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.