Date: Tue, 14 Aug 2007 14:09:49 +0200 (CEST) From: Oliver Fromme <olli@lurza.secnetix.de> To: freebsd-current@FreeBSD.ORG, h.schmalzbauer@omnisec.de Subject: Re: powerd and it's "wakeup" behaviour Message-ID: <200708141209.l7EC9nrb082368@lurza.secnetix.de> In-Reply-To: <200708132141.43165.h.schmalzbauer@omnisec.de>
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Harald Schmalzbauer <h.schmalzbauer@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.'
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