Re: [PATCH] cpuidle:powernv: Make the snooze timeout dynamic.
From: Michael Ellerman
Date: Mon Jun 04 2018 - 07:27:50 EST
"Gautham R. Shenoy" <ego@xxxxxxxxxxxxxxxxxx> writes:
> From: "Gautham R. Shenoy" <ego@xxxxxxxxxxxxxxxxxx>
>
> The commit 78eaa10f027c ("cpuidle: powernv/pseries: Auto-promotion of
> snooze to deeper idle state") introduced a timeout for the snooze idle
> state so that it could be eventually be promoted to a deeper idle
> state. The snooze timeout value is static and set to the target
> residency of the next idle state, which would train the cpuidle
> governor to pick the next idle state eventually.
>
> The unfortunate side-effect of this is that if the next idle state(s)
> is disabled, the CPU will forever remain in snooze, despite the fact
> that the system is completely idle, and other deeper idle states are
> available.
That sounds like a bug, I'll add?
Fixes: 78eaa10f027c ("cpuidle: powernv/pseries: Auto-promotion of snooze to deeper idle state")
Cc: stable@xxxxxxxxxxxxxxx # v4.2+
cheers