From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 1 Oct 2018 02:42:18 -0500 (CDT) From: Per Oberg Message-ID: <590994061.262338.1538379738455.JavaMail.zimbra@wolfram.com> In-Reply-To: <759115071.1538372023382.JavaMail.root@webmail> References: <759115071.1538372023382.JavaMail.root@webmail> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Xenomai] What does activating SMP mean? List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xenomai Hello ----- Den 1 okt 2018, p=C3=A5 kl 7:33, =EB=B0=95=EC=9E=AC=ED=98=B8 jaeho@se= oultech.ac.kr skrev: > Hi, all > I thought that activating SMP makes tasks using all cpu cores, but I real= ized > that it doesn't. > I did not explicitly specify the CPU when I created the task. > I have created two xenomai tasks and checked to see how much cpu share th= e task > has on any cpu with / proc / xenomai / stat. > As a result, we confirmed that only one cpu of two cpu works. > So we used T_CPU () to allocate different CPU cores for each task when we > created the task. > As a result, you can see that both tasks are running on two CPUs. > I expected to use both CPUs when I enabled SMP, but I did not. Why is not= it? > Also, does one task only run on one cpu? > The environment I used is shown below. > ------------------------------------------------------------------------ > zybo-z7-20(zynq-7000) > Dual-Core ARM Coretex-A9 MPCore Up to 866MHz > xenomai 2.6.5 > kernel 3.14.2 > ubuntu 14.04 > ------------------------------------------------------------------------ > thank you for your advice. > _______________________________________________ > Xenomai mailing list > Xenomai@xenomai.org > https://xenomai.org/mailman/listinfo/xenomai Not sure that I can answer your question as it was formulated, but perhaps = I can contribute with something. Do your test-task use all your CPU time or= do you have idling? I would -guess- that as long as one CPU is sufficient = the scheduler won't use any other unless it was specified on the command-li= ne. I answer, even though I am not sure about this because I would like to be = corrected if I'm wrong.=20 Regards Per =C3=96berg