linux-kernel - Re: [PATCH v3 0/6] PM: QoS: Introduce a CPU system wakeup QoS limit for s2idle

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <7hcy57dmjp.fsf@baylibre.com>
Date: Mon, 24 Nov 2025 15:43:22 -0800
From: Kevin Hilman <khilman@...libre.com>
To: Ulf Hansson <ulf.hansson@...aro.org>, "Rafael J . Wysocki"
 <rafael@...nel.org>, linux-pm@...r.kernel.org
Cc: Vincent Guittot <vincent.guittot@...aro.org>, Peter Zijlstra
 <peterz@...radead.org>, Pavel Machek <pavel@...nel.org>, Len Brown
 <len.brown@...el.com>, Daniel Lezcano <daniel.lezcano@...aro.org>, Maulik
 Shah <quic_mkshah@...cinc.com>, Prasad Sodagudi <psodagud@...cinc.com>,
 Dhruva Gole <d-gole@...com>, Deepti Jaggi <quic_djaggi@...cinc.com>, Ulf
 Hansson <ulf.hansson@...aro.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 0/6] PM: QoS: Introduce a CPU system wakeup QoS limit
 for s2idle

Ulf Hansson <ulf.hansson@...aro.org> writes:

> Changes in v3:
> 	- Take new the new QoS limit into account for cpuidle too (Rafael).
> 	- Add a new Kconfig for the new QoS interface (Rafael)
> 	- Improved the documentation (Dhruva) 
> 	- Clarified commit messages and added acks.
>
> Changes in v2:
> 	- Limit the new QoS to CPUs  and make some corresponding renaming of the
> 	functions along with name of the device node for user space.
> 	- Make sure we deal with the failure/error path correctly when there are
> 	no state available for s2idle.
> 	- Add documentation.
>
> Some platforms supports multiple low power states for CPUs that can be used
> when entering system-wide suspend and s2idle in particular. Currently we are
> always selecting the deepest possible state for the CPUs, which can break the
> system wakeup latency constraint that may be required for a use case.
>
> Therefore, this series suggests to introduce a new interface for user space,
> allowing us to specify the CPU system wakeup QoS limit. The QoS limit is then
> taken into account when selecting a suitable low power state for s2idle/cpuidle.

Reviewed-by: Kevin Hilman (TI) <khilman@...libre.com>
Tested-by: Kevin Hilman (TI) <khilman@...libre.com>