From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4F951555.2070403@domain.hid> Date: Mon, 23 Apr 2012 10:39:49 +0200 From: Philippe Gerum MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] Smi workaround on ICH8M List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Willy Lambert Cc: xenomai@xenomai.org On 04/23/2012 03:51 AM, Willy Lambert wrote: > Hi, > > I have a message in dmesg about SMI workaround : > Xenomai: SMI-enabled chipset found, but SMI workaround disabled > (check CONFIG_XENO_HW_SMI_WORKAROUND). You may encounter > high interrupt latencies! > > My kernel should be configured properly and following the "In case of > high latencies" of > http://www.xenomai.org/index.php/Configuring_x86_kernels thread, I did > some tests. > > Latency test is here (if it is us it should be ok no ?): > Yes, this looks ok, but you need to run this test longer, and try a few usual suspects like plugging in/out USB devices while doing so (e.g. mouse, netdev). The point of this message is to tell you that your chipset is known to create latency issues in some cases (like most Intel chipset these days), but you did not enable the Xenomai code which works around such issues by shutting down problematic SMI sources. That may be right, or even required to leave all the SMI sources enabled (e.g. thermal control), but this might also lead to unacceptable latency spots. YMMV. This is basically a heads up message. -- Philippe.