From mboxrd@z Thu Jan 1 00:00:00 1970 References: <5601A1A1.2020506@siemens.com> <560263A0.4080208@sigmatek.at> From: =?UTF-8?Q?Harald_Fe=c3=9fl?= Message-ID: <56026810.8040300@sigmatek.at> Date: Wed, 23 Sep 2015 10:51:28 +0200 MIME-Version: 1.0 In-Reply-To: <560263A0.4080208@sigmatek.at> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] Fwd: Re: Problem that the Linux scheduler is not called for some ms Reply-To: harald.fessl@sigmatek.at List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: jan.kiszka@siemens.com, xenomai@xenomai.org Hi The linux tasks are not blocked (not all). I think the problem is , that the linux scheduler function in the kernel is not called for some ms. I have also traced the calls to the scheduler function "static int __sched __schedule(void)" and sometimes when the decribed problem occur this function is not called while no linux task are running. Harald Fessl > As you already recorded (f)traces, just dive deeper and check why some > of the Linux tasks are blocked, ie. when they go to sleep, check the > reason. And then, when they wake up again, check who woke them up and > via which mechanism. Maybe that will provide some trace to what goes wrong. > Jan > -- > Siemens AG, Corporate Technology, CT RTC ITP SES-DE > Corporate Competence Center Embedded Linux > On 2015-09-22 16:13, Wolfgang Netbal wrote: > >> > >> > >> Hi guys > >> > >> I have a problem that the linux scheduler is not called for some ms. > >> The cpu load is very low. > >> > >> Im using a iMX6, linux kernel 3.0.42 and xenomai 2.6.2.1. > >> > >> I have attached a graphical task trace where you can see the task switches. > >> The tasks with prefix X- are xenomai task, the prefix L- means linux task. > >> In the first line you can see the tick from a fpga to start the folowing > >> tasks, X-realtime, X-cyclic, X-Loader and X-background. > >> The X-Cyclic task is switching to linux (L-Cyclic) in each cycle because > >> it is calling UDP functions. > >> Up the mark 195 ms everthing is working correct. > >> From the mark 195 ms up to 199 ms there is no linux task (L-) running. > >> I have also seen that the linux scheduler function is not called from > >> the mark 195ms to 199ms. > >> > >> Does anybody know what is the problem ? > >> Are there some linux/xenomai settings to modify this behavior ? > >