From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <45007DF6.1030807@domain.hid> Date: Thu, 07 Sep 2006 15:15:50 -0500 From: Jeff Webb MIME-Version: 1.0 Subject: Re: [Xenomai-help] Porting / API Questions References: <44FF3C26.10501@domain.hid> <200609071112.28817.schwab@domain.hid> In-Reply-To: <200609071112.28817.schwab@domain.hid> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ulrich Schwab Cc: xenomai@xenomai.org Ulrich Schwab wrote: > When I did the same switch (9 month ago now) I choose to combine > the kernel / user space split in one application and switched to the native > API at the same time. > I think it was a good decision, since now the application is independent of > the exact kernel version and is easier to debug. > Only the driver for the analog and digital I/O is still a kernel module (RTDM) > > The RT kernel threads of the original version are now threads of the user > space app running in primary mode. This means the split between RT/non-RT > is basically the same as before, but now they all run in user space. I'm glad to hear that you were successful with porting your application! I plan to take a similar approach eventually, but I want to do things one small step at a time. > Why do You need a FIFO this large ? I have a whole lot of data coming over the FIFO at a very high rate. The user-space side also has some graphics routines that have a long latency in certain situations. The amount of data transferred could be reduced substantially, but not without major changes to the simulation, which I cannot afford to do at the moment. > Why not using shared memory for the data, and the FIFO for passing > signals/commands ? I need to log data, plot, and do other things at certain exact simulation times. Using shared memory, I cannot guarantee that I will be able to get data with the timestamp I need. The real-time/user-space partitioning of our simulation is not at all optimal. Switching to userspace real-time will allow me to do things in a much cleaner way. Thanks for your input, Jeff