> On 03/16/2016 11:50 AM, John Dammeyer wrote: > > Seems that's a fault of the graphics drivers and their implementation. The > > whole point of an RTOS is that tasks can run at priorities that serve their > > needs. How would placing the video at a higher priority be any different > > than an non-real time system that allows the video to run to completion. > > > > > Some video drivers do HUGE DMA transfers between screen and > main memory, bursting 10's of megabytes back and forth. > These are totally unthrottled transfers, running as fast as > the memories and busses can go, and thereby locking out the > CPU from the memory for the duration. Since this is not > caused by a process executing in the CPU, it is totally > beyond the control of the RT scheduler. Usually using a > generic video driver reduces the problem as these drivers > don't activate such acceleration features. > > Jon
Even though huge DMA transfers currently are out of control from RT scheduler they should not be for good real time perfomance. I go for the micro controllers, slow but predictable, 25µs period run perfect because there are just little code to run each time. Nicklas Karlsson ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
