powerd and it's "wakeup" behaviour
Oliver Fromme
olli at lurza.secnetix.de
Tue Aug 14 05:09:57 PDT 2007
Harald Schmalzbauer <h.schmalzbauer at omnisec.de> wrote:
> I'm using cpufreq (acpi_perf (800/9800 500/5900) with acpi_throttle and I have
> limited debug.cpufreq.lowest=250, so dev.cpu.0.freq_levels reads:
> 800/9800 700/8575 600/7350 500/5900 437/5162 375/4425 312/3687 250/2950
>
> I haven't tested the saving which acpi_throttling provides, but I think I can
> gain some minutes over plain 800/500MHz(Vcore)switch.
>
> Now the problem is that "waking up" from 250 MHz to full speed needs too much
> time to be effective for short term task like displaying a PDF.
> Reading the file doesn't stress the CPU so powerd increases "clock"
> (paranthesized because clock has only two states, but throttling adds 6
> steps) in 7 steps to 800MHz.
>
> I'd love to have a option which tells powerd to slowly step down, but jump to
> full throttle if threshold of cpu usage is reached, regardless the current
> clock setting. So a CPU usage peak would give full performance first, then
> slowly stepping down again according to the CPU usage.
>
> Even my old 800MHz P3-m is fast enough to complete "cpu hungry" tasks in a
> quiet short time, so slowly stepping clock up is not optimal form me because
> it's not that fast that comleting the task with quarter speed doesn't feel
> sluggish.
>
> Any thoughts?
> Anyone who could and want to implement such a feature? (my programming skills
> are far beyond...)
I've needed a similar feature for some time and I have a
patch, so I cleaned it up a bit and submitted it along
with an update to the manpage. It's PR bin/115513:
http://www.freebsd.org/cgi/query-pr.cgi?pr=115513
Apply the diff relative to src/usr/sbin/powerd, then
"make clean && make && make install", and restart
powerd with option -u 100. That should have the effect
that you described above.
The patch is relative to RELENG_6 (it can be applied
manually to -current without problems). If you have
difficulty extracting it from the PR, the patch is also
available from this URL:
http://www.secnetix.de/~olli/tmp/powerd.diff
Best regards
Oliver
--
Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M.
Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung:
secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün-
chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart
FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd
'Instead of asking why a piece of software is using "1970s technology,"
start asking why software is ignoring 30 years of accumulated wisdom.'
More information about the freebsd-current
mailing list