linux-kernel - Re: [RFC] cpuidle - remove the power

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

Date:	Mon, 10 Dec 2012 11:09:58 -0800
From:	Julius Werner <jwerner@...omium.org>
To:	Daniel Lezcano <daniel.lezcano@...aro.org>,
	"Rafael J. Wysocki" <rjw@...k.pl>
Cc:	Francesco Lavra <francescolavra.fl@...il.com>,
	linux-pm@...r.kernel.org, Kevin Hilman <khilman@...com>,
	Deepthi Dharwar <deepthi@...ux.vnet.ibm.com>,
	Trinabh Gupta <g.trinabh@...il.com>,
	Lists Linaro-dev <linaro-dev@...ts.linaro.org>,
	len.brown@...el.com, linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Sameer Nanda <snanda@...omium.org>
Subject: Re: [RFC] cpuidle - remove the power_specified field in the driver

Hi,

What is the current status of this? Daniel, do you think you have got
enough feedback to submit a definitive patch for this? Rafael, would
you approve of such a change?

The bug with dynamically added C-states that is tied to this still
hurts the battery life for some users across all distros every day, so
I think it would be valuable to get a consistent solution into the
mainline soon before everyone has to roll their own.

On 11/12/2012 09:26 PM, Daniel Lezcano wrote:
> This patch follows the discussion about reinitializing the power usage
> when a C-state is added/removed.
>
>  https://lkml.org/lkml/2012/10/16/518
>
> We realized the power usage field is never filled and when it is
> filled for tegra, the power_specified flag is not set making all these
> values to be resetted when the driver is initialized with the set_power_state
> function.
>
> Julius and I feel this is over-engineered and the power_specified
> flag could be simply removed and continue assuming the states are
> backward sorted.
>
> The menu governor select function is simplified as the power is ordered.
> Actually the condition is always true with the current code.
>
> The cpuidle_play_dead function is also simplified by doing a reverse lookup
> on the array.
>
> The set_power_states function is removed as it does no make sense anymore.
>
> Signed-off-by: Daniel Lezcano <daniel.lezcano@...aro.org>
> ---
>  drivers/cpuidle/cpuidle.c        |   17 ++++-------------
>  drivers/cpuidle/driver.c         |   25 -------------------------
>  drivers/cpuidle/governors/menu.c |    8 ++------
>  include/linux/cpuidle.h          |    2 +-
>  4 files changed, 7 insertions(+), 45 deletions(-)
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/