[PATCH v2 1/2] smp: Introduce a helper function to check for pending IPIs
Ben Horgan
ben.horgan at arm.com
Mon Oct 20 12:10:58 PDT 2025
Hi Ulf,
Only a comment on the naming rather than a full review.
On 10/20/25 15:17, Ulf Hansson wrote:
> When governors used during cpuidle, tries to find the most optimal
> idlestate for a CPU or a group of CPUs, they are known to quite often fail.
> One reason for this, is that we are not taking into account whether there
> has been an IPI scheduled for any of the CPUs that are affected by the
> selected idlestate.
>
> To enable pending IPIs to be taken into account for cpuidle decisions,
> let's introduce a new helper function, cpus_may_have_pending_ipi().
To me, "may" indicates permission, i.e. is allowed, rather than
correctness. Would "likely" be better here, cpus_likely_have_pending_ipi()?
>
> Note that, the implementation is intentionally as lightweight as possible,
> in favor of always providing the correct information. For cpuidle decisions
> this is good enough.
>
> Suggested-by: Thomas Gleixner <tglx at linutronix.de>
> Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
> ---
>
> Changes in v2:
> - Implemented a common function, rather than making it arch-specific. As
> suggested by Thomas and Marc.
> - Renamed the function to indicate that it doesn't provide correctness.
> - Clarified function description and commit message.
>
--
Thanks,
Ben
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