Date: Mon, 30 Jul 2007 11:28:59 +0200 From: Pietro Cerutti <gahr@gahr.ch> To: Hajimu UMEMOTO <ume@freebsd.org>, freebsd-hackers@freebsd.org Subject: Re: [patch] enhance powerd(8) to handle max temperature Message-ID: <46ADAF5B.6050602@gahr.ch> In-Reply-To: <yge7iol6zb8.wl%ume@mahoroba.org> References: <46AA0491.5000203@gahr.ch> <yge7iol6zb8.wl%ume@mahoroba.org>
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[-- Attachment #1 --] Hajimu UMEMOTO wrote: > 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. You are right, but the passive colling mechanism could not be available on some systems where thermal is available, and I'm still waiting for answers about acpi_thermal not sending notifies. See my previous post: http://lists.freebsd.org/pipermail/freebsd-hackers/2007-July/021361.html What's wrong with including this feature directly in powerd? > > Sincerely, > > -- > Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan > ume@mahoroba.org ume@{,jp.}FreeBSD.org > http://www.imasy.org/~ume/ > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" -- Pietro Cerutti PGP Public Key: http://gahr.ch/pgp [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFGra9gwMJqmJVx944RCgwCAJsEhkOnovm97lelLtAk2wK77Q2PYwCgpheR HRsiQLzHA63xU+K2gQgpMwU= =5FsM -----END PGP SIGNATURE-----
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