From: Scott Wood <scottwood@freescale.com>
To: Thomas Waldecker <Thomas.Waldecker@tqs.de>
Cc: "Linux PPC dev mailing list \(linuxppc-dev@lists.ozlabs.org\)"
<linuxppc-dev@lists.ozlabs.org>
Subject: Re: Why is the e500v2 core not using cpuidle?
Date: Fri, 1 Feb 2013 12:15:17 -0600 [thread overview]
Message-ID: <1359742517.23561.2@snotra> (raw)
In-Reply-To: <B88C075EE1324644BA0452D5EFDD58281395211D@TQ-MAIL.tq-net.de> (from Thomas.Waldecker@tqs.de on Fri Feb 1 06:06:05 2013)
On 02/01/2013 06:06:05 AM, Thomas Waldecker wrote:
> Hi,
>=20
> As part of my masterthesis I was just looking around the kernel
> sources for cpuidle and figured out that the only CPU in the PowerPC
> architecture using the cpuidle framework is the pseries.
>=20
> I assume the e500v2 core is using the idle modes
> in arch/powerpc/kernel/idle_e500.S
>=20
> Why is there no support for the cpuidle framework?
Because nobody implemented it. :-)
The only reason I can think of to implement it on this chip would be to =20
dynamically choose when to enter nap versus doze, rather than always =20
just using doze. It's not clear whether the difference in power =20
savings is worth it -- do you have any way of measuring?
> How can I debug the e500 idle modes?
> Are there any statistics?
Top reports idle percentage...
> I already ran PowerTOP on a QorIQ P2020 but it's almost useless
> because the information is missing.
What information are you looking for?
-Scott=
next prev parent reply other threads:[~2013-02-01 18:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-01 12:06 Why is the e500v2 core not using cpuidle? Thomas Waldecker
2013-02-01 18:15 ` Scott Wood [this message]
2013-02-02 9:41 ` AW: " Thomas Waldecker
2013-02-04 20:02 ` Scott Wood
-- strict thread matches above, loose matches on Subject: below --
2013-02-07 12:19 Thomas Waldecker
2013-02-07 18:01 ` Scott Wood
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