From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <54C76713.2010904@xenomai.org> Date: Tue, 27 Jan 2015 11:23:15 +0100 From: Philippe Gerum MIME-Version: 1.0 References: <54C760BC.7040301@colgp.it> In-Reply-To: <54C760BC.7040301@colgp.it> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] Linux scheduling is hijacked from xenomai scheduling List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luca Galvagno , xenomai@xenomai.org On 01/27/2015 10:56 AM, Luca Galvagno wrote: > Hi to all, > we are using kernel 2.6.34 with the corresponding ADEOS patch Which Xenomai release? > (2.6.34-powerpc-2.10-03.patch ) and Xenomai on a PowerPC MPC5200b. 4 years old kernel and pipeline patch, don't expect much feedback on this configuration. > We are facing on a strange behavior when mixing Linux SysCalls with > Xenomai tasks . The effect of the above mix is that the "pure" (without > linux syscall) xenomai task continues to run , the remaining "mixed" > task (for example we have one with a posix socket server) and moreover > the linux os itself are not scheduled anymore. Specifically, to test > this behavior, we connected an oscilloscope to a cpu pin , the result is > that the xenomai task is moving the pin up and down (as it was > programmed) but the linux machine is neither accessible via ping or via > SSH. > > Do you have some suggestions, or some tests we can do ? Xenomai starving the regular kernel from CPU cycles until all the pending real-time duties have been carried out is the basic idea behind the dual kernel design, this is nothing strange. Now the question is: why does your real-time code seem to never complete its work loop, and there never leaves some CPU time to linux? -- Philippe.