On Sat, 2002-05-25 at 11:05, Erwin Rol wrote: > Normally I am not subscribed to the kernel list, but after a msg from > Karim that there was a "fight" going on about RTAI I read the archives > and decided that it was important enough to join the discussion. > > Both Linus and Larry seem to be not very interested in hard-realtime > Linux additions, this is OK. I mean everybody has his interests and with > so many Linux users and developers you can't all focus on the same > thing. > > But we (RTAI developers, which include Karim and myself) have decided to > focus on hard-realtime extensions to Linux. And it is than always very > motivating to hear nobody gives a f*ck about your work or problems, > because "hey, you don't have a business model that makes sense anyway" > > For example, first there is said that there is no userspace > hard-realtime, than Karim corrects that, than there is said that a > userspace program that uses mlockall is actually a module: with other > words be quiet and go sit in the corner. > This seems the same as what happened with FSMLabs, first they explain > why userspace hard-realtime is crap, and now they have implemented it > them self and explain how good it is. > > We have had several discussions with FSMLabs about userspace > hard-realtime and asked for comments on for example the following > situation. > > - > When i write a RTAI module, that changes the sched_setparam in such a > way that SCHED_FIFO and SCHED_RR are now hardrealtime. Than a binary > program that runs on a computer with the RTAI kernel-module loaded > violates the patent, and on a computer that doesn't have it loaded it > doesn't violate the patent. > - > needless to say we never even got a reply on questions like these. When > you have to believe FSMLabbs, you are not allowed to use non-GPL > software on a system that has a RTAI module loaded, according to Eben Mo Some how a small piece of the mail is missing here. ... according to Eben Moglen this can't be correct. - Erwin > > There was also asked about the possibility (and even some person on the > RTAI list started such a project) to have a *BSD version of RTAI, well > the answer is simply NO. since *BSD will not accept GPL kernel code, and > the RTLinux patent doesn't allow no GPL implementations there will be no > free *BSD with this type of hard-realtime. Of course you can buy the > FSMLab version, but than you can just as well buy a true RTOS, like > VxWorks. > > Also apparently there is the idea that all RTAI developers want to > become rich by getting the patent out of the way and sell RTAI. I know > you all know this is simply not true, like most Linux hacker we spend a > large part of our free time to give the real-time community a usable > piece of software where they normally have to pay for. > So please don't stamp us as some money sucking bastards that shouldn't > be allowed to use Linux in the first place. > > I just hope the linux developers are smart enough to not accept the > RTLinux into the main kernel, cause someday someone might come up with > the idea to write something that allows to have userspace programs to be > hard-realtime, and than you have to stop allowing non GPL userspace > programs, like for example GLIB( which is LGPL). > > - Erwin Rol , RTAI Developer > > > > >