RT Linux Patches

sally bitter writes "Linux 2.6 kernel Real-Time? It is going to happen soon. Montavista developers submitted patches today to LKML to begin testing all the low latency task preempt and interrupt stuffs they're introducing."

Comments

I wonder if it's true real-time

[AaronW]

Where I work we did a project using Timesys Linux which implements true real-time support and has some really cool scheduler options. For example, with Timesys, you can, for example, guarantee that a task will get a minimum of 15.7ms execution time every 31ms. It even allows you to set priorities for interrupts, such that an interrupt can be scheduled at a lower priority than a user thread. And finally, they added support for priority inheritance to avoid the problem of priority inversion, which occurs when a low priority thread has acquired a semaphore and a high priority thread blocks on it.

Not only can you reserve CPU bandwidth, but also network bandwidth. Of course it also has all the other standard features one would expect of a real-time OS.

Sadly, Timesys has not applied their patches yet to the 2.6 kernel at this time.

-Aaron

Re:Benefits?

[iotaborg]

It is also very useful in science/engineering fields. At my lab, we use RTAI linux currently, and this allows us to acquire data from our systems in real time, giving us a reliable way to compare our data with time in our systems.

Re:Benefits?

[Nazadus]

My employer had to choose Windows over Linux becuase Linux lacked true realtime support. Windows doesn't either, however their is third party software and developing projects is (supposedly) easier with Windows. Our sales dudes also wanted to be able to say "We use Windows!"... We looked at Linux but Linux was just too slow. We are currently moving away from QNX 4.25 (yeah, I know... really old... we are even on the f patch... I finally convinced them to goto g for the server, so I could do backups.. otherwise cp would crash after 64k of files...). We currently build custom industrial robots, so we *have* to have real time or else things could suck. Although I think Linux is a while from where Tenasys InTime (our current third party software) level, it's nice to know people are still working on it... so Linux may become a chance in 8 or so years... when we want to move to another platform. I wonder if the medical field would be intersted in RT Linux... I don't know if they require some special stuff because of legallity or something though...