linux-kernel - Re: [PATCH v2 1/2] smp: Introduce a helper function to check for pending IPIs

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Message-ID: <871pmow9bk.ffs@tglx>
Date: Mon, 27 Oct 2025 18:20:15 +0100
From: Thomas Gleixner <tglx@...utronix.de>
To: Ulf Hansson <ulf.hansson@...aro.org>, "Rafael J . Wysocki"
 <rafael@...nel.org>
Cc: Mark Rutland <mark.rutland@....com>, Marc Zyngier <maz@...nel.org>,
 Maulik Shah <quic_mkshah@...cinc.com>, Sudeep Holla
 <sudeep.holla@....com>, Daniel Lezcano <daniel.lezcano@...aro.org>,
 Vincent Guittot <vincent.guittot@...aro.org>, linux-pm@...r.kernel.org,
 linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, Ulf
 Hansson <ulf.hansson@...aro.org>
Subject: Re: [PATCH v2 1/2] smp: Introduce a helper function to check for
 pending IPIs

On Mon, Oct 20 2025 at 16:17, Ulf Hansson wrote:

> When governors used during cpuidle, tries to find the most optimal

When governors used during cpuidle trie to ...

Both plural and no comma.

> idlestate for a CPU or a group of CPUs, they are known to quite often fail.

idle state

> One reason for this, is that we are not taking into account whether there

...for this is, that they are not taking into account

> 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().

s/let's//

> Note that, the implementation is intentionally as lightweight as possible,
> in favor of always providing the correct information.

That sentence doesn't make sense. It's a snapshot and therefore can't
provide the correct information.

>  For cpuidle decisions this is good enough.

Thanks,

        tglx