From mboxrd@z Thu Jan 1 00:00:00 1970 From: dogshu Subject: Processor is almost never in C1 state Date: Mon, 6 Dec 2004 11:10:31 -0500 Message-ID: Reply-To: dogshu Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org Hello, I have a Toshiba Portege laptop with a 500 mhz pentium-3 mobile CPU. The processor is almost never is in the C1 state, and spends 99.9% of the time in the C2 state, even when doing heavy processing. After a night of compiling KDE, and while running the "burnP6" program included in the "cpuburn 1.4" package, this is the output of /proc/acpi/processor/CPU0/power: active state: C2 default state: C1 bus master activity: 00000000 states: C1: promotion[C2] demotion[--] latency[000] usage[00009710] *C2: promotion[--] demotion[C1] latency[001] usage[12232108] C3: As you can see, even though the processor is being maxed out by burnP6, it remains in the C2 state and doesn't really use the C1 state at all. I don't mind having the CPU in this lower power/lower performance state most of the time... however I occassionally like to play DVDs on this laptop, and I need all the CPU power I can get when playing DVDs, or else I will get lots of dropped frames. I am running kernel 2.6.10-rc2-mm4. I noticed that in the kernel parameters I can disable the C2 state altogether, but I'd rather not have to reboot whenever I play a DVD. Is there a way to tweak ACPI so that the processor spends more time in the C1 state, without giving up the C2 state entirely? thanks for any help, Jim Faulkner ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/