Date: Mon, 29 Aug 2005 21:57:09 -0700 From: Nate Lawson <nate@root.org> To: Tijl Coosemans <tijl@ulyssis.org> Cc: freebsd-stable@freebsd.org Subject: Re: 5-STABLE cpufreq hotter than est from ports Message-ID: <4313E725.70809@root.org> In-Reply-To: <200508020022.02992.tijl@ulyssis.org> References: <200508020022.02992.tijl@ulyssis.org>
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Tijl Coosemans wrote: > A couple days ago I updated my system and was excited to see cpufreq > and powerd in 5-stable. Since then however I noticed that my laptop > temperature is about 5°C higher than with est and estctrl. I found that > cpufreq when setting 200MHz for example set the absolute frequency to > 1600MHz (max for this laptop) and the relative frequency (p4tcc) to > 12.5% instead of using a more power conserving setting like 800MHz/25%. A variant of your patch has been committed and will be MFCd. Thanks! > So, I've worked out a patch (attached) that makes sure > that a lower frequency level has at most the same absolute setting > (preferably less of course). This eliminates quite a few levels so > somebody with a better knowledge of cpufreq should check if this patch > really does something good. This is the first time I've taken a look at > FreeBSD source code by the way. I added back the check for CPUFREQ_CMP since you don't want duplicate levels. This is not currently a problem with est/p4tcc but other combinations of settings could have produced duplicates with the patch's approach. > Also, somewhat related, the p4tcc driver doesn't recognise > acpi_throttle, which means that when you load the cpufreq module after > booting, the freq levels are messed up. I'm not sure what the best > solution for this is. Let p4tcc detect acpi_throttle and don't attach > if it's present (like acpi_throttle does now if it finds p4tcc) or > detach it before attaching? Or maybe p4tcc and acpi_throttle should be > merged into one driver? acpi_throttle is only the same as p4tcc on x86 platforms. We need a better negotiation strategy in general between the different drivers. The logic for these two is already p4tcc > acpi_throttle but we need to support reprobing when cpufreq.ko is loaded after boot by detaching both and then allowing p4tcc to win the probe. -- Nate
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