Date: Fri, 09 Apr 2010 09:29:55 -0700 From: "Kevin Oberman" <oberman@es.net> To: Bartosz Fabianowski <freebsd@chillt.de> Cc: freebsd-acpi@freebsd.org, "Alexandre \"Sunny\" Kovalenko" <gaijin.k@ovi.com>, Ian Smith <smithi@nimnet.asn.au> Subject: Re: Spurious thermal shutdowns on Dell Studio 1557 Message-ID: <20100409162955.8DD0A1CC0D@ptavv.es.net> In-Reply-To: Your message of "Fri, 09 Apr 2010 15:13:45 BST." <4BBF3619.6000200@chillt.de>
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> Date: Fri, 09 Apr 2010 15:13:45 +0100 > From: Bartosz Fabianowski <freebsd@chillt.de> > Sender: owner-freebsd-acpi@freebsd.org > > > Great. I'd still like to know what your remaining frequencies are, as I > > couldn't correlate your previous full set with the throttling N * 12.5%? > > The remaining frequencies are: > > 1597/35000 1463/31000 1330/27000 1197/23000 1064/19000 931/15000 > > Additionally, I do not remember how many CX states I had before - but I > am pretty sure that it was more than just one. Now, the only CX state > remaining is C1/3. > > Interestingly, disabling either the p4tcc or the acpi_throttle driver on > its own does nothing to cut down on frequencies. Only when both are > disabled via hints does the list drop from 13 frequencies to the 6 above. This is by design. TCC and throttling do the exact same thing, but TCC does it better, so if only throttling is available , it is used and when both are available, TCC is used. Again, there techniques a=were designed for thermal management, not power management. (TCC is Thermal Control Circuit) They are very close to useless for power management and I have been campaigning for some time to have them pulled from the FreeBSD power management system. EST and similar tools actually do power management well. Now, for a really weird suggestion, one that makes no sense, but works perfectly on my laptop: In /boot/loader.conf: hint.p4tcc.0.disable="1" hint.acpi_throttle.0.disable="1" hw.pci.do_power_nodriver="2" (also, try 3, but my system hangs with 3) Then build a kernel WITHOUT "device cpufreq" (or nodevice cpufreq) I would expect this to provide NO frequency control, but I get (and use) the five frequencies provided by EST: dev.cpu.0.freq_levels: 2000/27000 1600/22600 1333/19666 1066/16733 800/13800 Testing has shown that this is a REAL power savings. -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751
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