On Friday 15 November 2013 03:26:18 Ralf Mardorf did opine: > http://lwn.net/Articles/572740/ > This concerns the linuxcnc folks, including me. However PREEMPT-RT isn't the only method and in fact is far from the best to gain some high speed IO. Paolo has finally understood that RTAI needs to be brought up to date, and I am hearing rumors that it has even been built on a 3.10 kernel. Alternatively the Xenomai patches are working reasonably well, ISTR I did a test build of 3.8.3 +Xenomai on my lappy, and while it could have run a machine, the lappy doesn't have a parport, and its cpu doesn't have even the iron an Atom board has, so that got wiped when I put Mate 14 on it. Right now, the "gold card" motherboard for us running machinery in real time is from the Atom cpu camp, where latencies for a 50 kilohertz base_thread are the usual bell curve shaped, with 99.9% of the tasks completed within 2 u-secs of scheduled, worst case perhaps 7 u-secs when the machine is doing something else. Like opening a new screen in firefox. This is running that 2.6.32-122-rtai kernel we've been using since 8.04 ubuntu LTS. But thats a poor kernel for everyday use, no PAE. >From the development work going on in linuxcnc right now, its looking like we may have found our next platform in the BeagleBone Black when a suitable bit/pin oriented cape is shipping. This of course won't do for audio since we do IO a bit at a time independent of any other bit in its copious IO space. Several of them are running production milling machines right now using homemade IO hardware. For a $45 USD cost, board about the size of a credit card, thats amazing. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) He who has the courage to laugh is almost as much a master of the world as he who is ready to die. -- Giacomo Leopardi A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
