From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4E8AE5A6.6090306@domain.hid> Date: Tue, 04 Oct 2011 12:53:26 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <20110926090226.9C75AD68@domain.hid> In-Reply-To: <20110926090226.9C75AD68@domain.hid> Content-Type: text/plain; charset=UTF-8 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: Petr Cervenka Cc: xenomai-help On 09/26/2011 09:02 AM, Petr Cervenka wrote: > > Hello. > > I recently tried newer computer and I suprusingly realized that it is bigger load than the old one with our xenomai application. > The problem is in the frequency downscaling of the processor when the load in under 100%. > Of course I have disabled CPU_FREQ, ACPI_PROCESSOR and INTEL_IDLE as suggested. > Later I tried also to disable CPU_IDLE, 7300_IDLE (intel chipset idle memory) and all power efficiency settings in the BIOS, but without success. > The experienced behaviour is following: > when the process is waiting for an event, the processor lowers its frequency and when the event happens it tries to restore (slowly) its nominal frequency. > > Do you have any advice or tip what to try, because I'm really desperate? Have you tried: - enabling SMI workaround (and do not forget to check the boot logs to check that it actually works with the chipset you use); - if that fails, adding "idle=poll" to kernel arguments? -- Gilles.