From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <51ECE69D.4090008@bollue.de> Date: Mon, 22 Jul 2013 10:00:29 +0200 From: Kai Bollue MIME-Version: 1.0 References: <51EA4243.4020904@web.de> In-Reply-To: <51EA4243.4020904@web.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] shielding fully CPU or CORE List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xenomai@xenomai.org On 20.07.2013 09:54, Jan Kiszka wrote: > On 2013-07-19 11:17, Skander Bahloul wrote: >> Dear Xenomai list members, >> >> On a successful instal (but without NVIDIA driver, cf my previous message), I am now starting using Xenomai. >> >> We need to : >> 1* shield fully a CPU or core, against the scheduler, interruption, etc >> 2* run a single thread on this isolated CPU or core >> >> Step 2 is OK with the Xenomai API. >> But how should I achieve step 1 ? >> >> I did not find advice in the Xenomai documentation. >> I guess it should be done with : >> $ sudo shield -a 0-3 -m -1 >> >> Do you agree ? >> When may I find detailed info on CPU shielding ? > With "shield fully", do you mean 99,9...% or true 100%? The latter is > not possible with current Linux kernels, thus also not with Xenomai. For > the former, try kernel parameter isocpus (to keep Linux off certain > cores), possibly in combination with xeno_hal.rthal_supported_cpus (to > limit Xenomai to those cores). If you use an AMD CPU with "Bulldozer" / "Piledriver" architecture, for better latencies, it helps to keep Linux off of both cores on one module, as they share certain ressources. E.g. use isolcpus=0,1 and bind your Xenomai task to CPU0. Regards, Kai