> > The problem is different. > > RT means looking around and fulfill all tasks in a defined timeslot. > > Performance means in most cases move data as fast as you can. > > And in some cases it's mutually exclusive. > > So what you are saying is standard Linux is just like windows and a task > (thread, application, device driver) can take over the processor and use as > much time as it likes. Totally co-operative rather than pre-emptive.
NO standard Linux use more like fair scheduling. > That an RTOS component adds the time slicing so that every X time period a > task of equal priority gets to use that time slice or part of it to do it's > function. This is more like ordinary scheduling, clock cycles shared fairly. > Or does the first system call an application make to the OS result in an > evaluation of process priorities which results in the highest priority task > getting control which may be different from the task that called the OS. In real time scheduling time slost is one method but most common is highest priority task is executed until it have nothing more to do right now. Highest priority task execute until done is the method used in the two most common scheduling schemes Rate monotonic and earliest dead line first. In rate monotonic priority is static and depend on how oftern task need to execute. In earliest dead line first priority is dynamic and depend on time until next dead line. Both are optimal. There are some preconditions and rules which must be followed, you could read more about it here. https://en.wikipedia.org/wiki/Rate-monotonic_scheduling https://en.wikipedia.org/wiki/Earliest_deadline_first_scheduling > . > In other words a > while (1 ) { }; > > loop will break Linux since nothing can pre-empt an infinite loop? > > If that doesn't break standard Linux then there's some sort of pre-emptive > multi-tasking going on already. > > Perhaps when people use the term Real Time Linux for LinuxCNC they are > talking about something different? > > John Dammeyer > > > > > > ------------------------------------------------------------------------------ > 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 > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
