LinuxCon + CloudOpen + ContainerCon NA 2015

The Real Time patch (RT patch or PREEMPT_RT), has been maintained out of the Linux kernel tree since late 2004. It is the longest and largest patch set to be kept out of the tree and still widely used. A lot of the patch has made it into mainline (mutex code, priority inheritance futexes, ftrace, lockdep, hrtimers, generic interrupts, threaded irqs, Real Time scheduler, etc). The RT patch had so much influence on mainline, that new code for Real Time can now be directly added to mainline (for example: NO_HZ_FULL and the DEADLINE scheduler), but there is still a lot more that needs to go into mainline to make it a true RTOS. This talk will explain what those features are and what is holding it up from getting in. Some of it is technical and some of it is political. Both of these types of issues will be discussed.