From: Sergey Senozhatsky <sergey.senozhatsky at gmail.com>
To: powertop@lists.01.org
Subject: Re: [Powertop] Powertop doesn't detects sleeping ARM cores
Date: Thu, 20 Sep 2012 12:14:33 +0300 [thread overview]
Message-ID: <20120920091433.GA3237@swordfish.minsk.epam.com> (raw)
In-Reply-To: 505AD2D0.10505@samsung.com
[-- Attachment #1: Type: text/plain, Size: 1430 bytes --]
On (09/20/12 12:24), Igor Zhbanov wrote:
> Chris Ferron wrote:
>
> Now I'm looking for solution. But I see now only four ways:
>
> 1) Develop another kernel mechanism for providing information about all available
> CPUs and cores. Or ask the kernel authors not to remove offline cores from
> /proc/cpuinfo and their information files from /sys/.../cpu/.
procps (e.g. top utility) use sysconf _SC_NPROCESSORS_CONF/_SC_NPROCESSORS_ONLN for
that purpose.
https://www.gnu.org/software/libc/manual/html_node/Processor-Resources.html
-ss
> 2) Scan /sys/.../cpu for all CPUs and temporarily wake it up to gather information.
> 3) Ask the user to run PowerTOP on a heavy loaded system for the first time
> (or wake up all CPUs by the PowerTOP) and store collected CPU information somewhere
> in /var/cache/powertop and reuse it on later runs.
> 4) Don't just sleep in a main cycle, but scan /sys/.../cpu for new CPUs to appear.
> (Perhaps there could be something like D-Bus or netlink notification when a core
> brought online -- I don't know about it).
>
> At your personal view, what way fits better in the PowerTOP project?
>
> P.S. This may be the case for x86 CPUs too. I have disable CPU2 by writing
> to /sys/devices/system/cpu2/online, and the PowerTOP sees only CPU0, CPU1, and CPU3.
> Although default PC's CPU governor as I know doesn't turn off CPUs frequently.
>
next reply other threads:[~2012-09-20 9:14 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-20 9:14 Sergey Senozhatsky [this message]
-- strict thread matches above, loose matches on Subject: below --
2012-09-20 10:55 [Powertop] Powertop doesn't detects sleeping ARM cores Igor Zhbanov
2012-09-20 10:42 Arjan van de Ven
2012-09-20 10:40 Igor Zhbanov
2012-09-20 9:57 Igor Zhbanov
2012-09-20 9:56 Arjan van de Ven
2012-09-20 9:43 Sergey Senozhatsky
2012-09-20 9:29 Igor Zhbanov
2012-09-20 8:24 Igor Zhbanov
2012-09-19 15:15 Chris Ferron
2012-09-19 8:26 Igor Zhbanov
2012-09-17 12:57 Igor Zhbanov
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