Date: Tue, 15 May 2007 12:47:18 +0200 From: Harald Schmalzbauer <h.schmalzbauer@omnisec.de> To: Rui Paulo <rpaulo@fnop.net> Cc: freebsd-current@freebsd.org, Colin Percival <cperciva@freebsd.org> Subject: Re: cpufreq & enhanced speedstep Message-ID: <200705151247.19122.h.schmalzbauer@omnisec.de> In-Reply-To: <86lkfrymlw.wl%rpaulo@fnop.net> References: <42BC519E.8010309@satro.sk> <200705142348.07522.h.schmalzbauer@omnisec.de> <86lkfrymlw.wl%rpaulo@fnop.net>
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Am Dienstag, 15. Mai 2007 schrieb Rui Paulo: > At Mon, 14 May 2007 23:48:07 +0200, > > Harald Schmalzbauer wrote: [...] > > I have a E6600 core2 and tried to reduce power dissipation by enabling > > some speedstep technology. > > acpi_perf seems to work since dev.cpu.freq shows 800 (possible > > 2400/1600/800) and goes up while compiling, but I frequently get the > > following errors: > > > > kernel: acpi_perf0: Px transition to 1600 failed > > kernel: acpi_perf0: set freq failed, err 6 > > I don't really know why it fails.. With acpi_throttle and p4tcc disabled, like you advised, this message doesn't occur any more. But I only have two possible speed steps, 2400 and 1600. But it's switching smoothly between them, atm. I don't have a power meter handy, so I can't see if it really works (and saves power). But in any case, the Watt values (dev.cpu.0.freq_levels: 2400/88000 1600/56000) are wrong for my core2 CPU. Where does acpi_perf get them from? Ok, form est (since without cpufreq loaded the values are /-1) but are they readable from any registers or are they hard coded according to the CPU type or are they in any table in the (acpi) BIOS? > > So I disabled acpi_perf and tried cpufreq with the following result: > > In your machine acpi_perf gives the values to est. If you disable > acpi_perf, est will not work. Oic, very valuable info. Thanks! > > I had acpi_perf and powerd enabled the last two days and the "feeling" of > > my X11/KDE desktop was a bit bumpy; The mouse frequently hung for some > > 10s of ms, in general the respnsiveness suffered a lot with > > dev.cpu.0.freq=800, a lot more than 298 with est... > > 298 comes from p4tcc or acpi_throttle. These values usually reduce a > lot the CPU power to prevent thermal problems. > > Maybe they should be separated... This would clarify things.. Thanks a lot, -Harry
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