From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4E89DF1E.7040608@domain.hid> Date: Mon, 03 Oct 2011 18:13:18 +0200 From: =?UTF-8?B?UGV0ciDEjGVydmVua2E=?= MIME-Version: 1.0 References: <20110926090226.9C75AD68@domain.hid> <20111003103914.8A2B636C@centrum.cz> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] Frequency downscaling of new intel CPU List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Noulard Cc: xenomai-help I'm sure that CPU_FREQ, ACPI_PROCESSOR, CPU_IDLE, INTEL_IDLE and 7300_IDLE were disabled in kernel configuration and no cpufreq module is loaded (or even created). Later I tried (desperately) to enable most of these settings and although I set performance governor to cpufreq, no measurable change happened (using acpi_cpufreq module). But cpuidle (when compiled in kernel) shows that a lot of time is spent in power saving states (/sys/devices/system/cpu/cpu/cpuidle/state/..., where is also 2 and 3). And on one of the mainboards I tried, the acpi_cpufreq was unable to load, perhaps because of the disabled BIOS settings). I'm now working with windows, so the sysfs path is what I remember (maybe not so well). Petr Dne 3.10.2011 10:47, Eric Noulard napsal(a): > 2011/10/3 Petr Cervenka: >> Hello again. >> I know, that my problem is not so close related with the xenomai. But I think many of xenomai users with new intel CPUs have similar problem. >> I tried it it with two different main boards and none of the BIOS settings helped. (C-states: disabled, Speedstep: disabled, CPU idle: high performance, TurboBoost: disabled, ...). My theory is that the linux kernel overrides BIOS settings, but I don't know how to prove it. >> Any ideas that could help me? > Did you verify that you don't have any cpufred related module loaded? > > What does > > $ lsmod | grep cpu > > indicate? > > You can try that one too: > > $ find /sys/devices/system -name "cpufreq" > >