Date: Sat, 28 Jul 2007 11:23:55 +0900 From: Hajimu UMEMOTO <ume@freebsd.org> To: Pietro Cerutti <gahr@gahr.ch> Cc: freebsd-hackers@freebsd.org Subject: Re: [patch] enhance powerd(8) to handle max temperature Message-ID: <yge7iol6zb8.wl%ume@mahoroba.org> In-Reply-To: <46AA0491.5000203@gahr.ch> References: <46AA0491.5000203@gahr.ch>
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Hi, >>>>> On Fri, 27 Jul 2007 16:43:29 +0200 >>>>> Pietro Cerutti <gahr@gahr.ch> said: gahr> Hi list, gahr> here is a patch to allow powerd(8) accept a "-t tval" option to set a gahr> temperature limit above which performance should be decreased. gahr> It's a first draft, and I identified the following problems: gahr> - the CPU temperature takes some time to decrease, so powerd keeps gahr> decreasing the CPU frequency until the temperature is below the limit. gahr> The effect is a "increase to maximum, decrease to minimum, increase to gahr> maximum, decrease to minimum, ...." which may not be desirable. gahr> - the temperature is retrieved by the hw.acpi.thermal.tz0.temperature gahr> sysctl MIB. Support for other methods would be desirable. gahr> The patches to powerd.c and powerd.8 are here: gahr> http://www.gahr.ch/FreeBSD/patches/powerd.c.diff gahr> http://www.gahr.ch/FreeBSD/patches/powerd.8.diff gahr> Any comment is welcome! We have a passive cooling mechanism already in our kernel. It runs according to an ACPI specification. Sincerely, -- Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan ume@mahoroba.org ume@{,jp.}FreeBSD.org http://www.imasy.org/~ume/
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