Re: [PATCH 0/2] cpuidle: idle_miss accounting fixes

[Rafael J. Wysocki (Intel)]

On Thu, Nov 5, 2026 at 9:11 AM Christian Loehle
<christian.loehle@xxxxxxx> wrote:
>
> On 10/30/26 08:36, Christian Loehle wrote:
> > These two fixes exclude timer-broadcast fallbacks from governor miss
> > accounting and respect the entry-time latency constraint when looking for
> > a better deeper state.
> > No functional change outside of sysfs above/below and tracing.
> >
> > Patch 1: Exclude timer-broadcast fallbacks
> >
> > When tick_broadcast_enter() fails, the core forces a shallower state.
> > Exclude these entries from governor miss accounting while retaining
> > residency, usage and governor feedback.
> >
> > On Orion O6, traces with menu and TEO running schbench, tbench and hackbench
> > recorded 6930 cpu_idle_miss events on 8172 broadcast fallbacks before the
> > fix, and none on 7763 fallbacks with patch 1. All matched fallbacks entered
> > WFI.
> >
> > Patch 2: Respect latency constraints for below misses
> >
> > An enabled deeper state may violate the latency QoS constraint, causing a
> > false below miss. Save the governor latency limit at entry and exclude
> > states exceeding it, without an additional state-table walk. Disable flags
> > continue to be checked at exit as they are expected to change less frequently.
> >
> > Christian Loehle (2):
> >   cpuidle: Skip miss accounting for timer broadcast fallbacks
> >   cpuidle: Respect latency constraints when accounting below misses
> >
> >  drivers/cpuidle/cpuidle.c | 16 +++++++++++++++-
> >  1 file changed, 15 insertions(+), 1 deletion(-)
> >
>
> Rafael, any opinions?

I have only looked at the patches briefly and I don't seem to have any
concerns ATM.