Re: [PATCH v2 03/44] cpuidle/poll: Ensure IRQ state is invariant

From: Peter Zijlstra
Date: Tue Sep 20 2022 - 04:57:40 EST


On Mon, Sep 19, 2022 at 03:19:27PM +0200, Frederic Weisbecker wrote:
> On Mon, Sep 19, 2022 at 11:59:42AM +0200, Peter Zijlstra wrote:
> > cpuidle_state::enter() methods should be IRQ invariant
>
> Got a bit confused with the invariant thing since the first chunck I
> see in this patch is a conversion to an non-traceable local_irq_enable().
>
> Maybe just add a short mention about that and why?

Changelog now reads:

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Subject: cpuidle/poll: Ensure IRQ state is invariant
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Tue May 31 15:43:32 CEST 2022

cpuidle_state::enter() methods should be IRQ invariant.

Additionally make sure to use raw_local_irq_*() methods since this
cpuidle callback will be called with RCU already disabled.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
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