From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4E580D8D.80002@domain.hid> Date: Fri, 26 Aug 2011 23:18:05 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] milli-second overruns under heavy load on x86, running Xenomai 2.5.6 List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: George Broz Cc: xenomai@xenomai.org On 08/26/2011 10:42 PM, George Broz wrote: > Hello, > > I'm experiencing very large overruns in the neighborhood of 10 to 50 > *milli-seconds* as reported by the Xenomai latency tool in user-task mode > whenever the Linux OS is heavily loaded. Under lighter loads these are in > the 30 to 70 micro-second (normal) range. > > My system is: > - Linux 2.6.37.6 (32-bit), Ubuntu 10.10 distribution > - Xenomai 2.5.6 using I-pipe patch adeos-ipipe-2.6.37.6-x86-2.9-02 > - Intel x86 Atom (dual-core) CPU D510 @ 1.66GHz > - Emb. dev board from Intel (ICH8M ctrlr, Ethernet h/w for e1000e) > - Xenomai configured w&w/o --enable-smp --enable-x86-tsc options > - gcc version 4.4.5 > > I've followed all of the recommendations for kernel configuration and have > disabled CPU sleep features in the BIOS such as SpeedStep and C-States. > Legacy USB has been disabled in the BIOS. Hyperthreading has also been > disabled, although I don't think it matters. Have you tried to enable the SMI workaround? -- Gilles.