On 3/1/14 11:04 , Sebastian Kuzminsky wrote: > (Now that i think about it, ubc has three flavors that use userspace > threads, all presumably implemented by posix threads: posix, rt-preempt, > and xenomai-user. I dont know how things work in the rt-preempt and > xenomai-user flavors, hopefully their scheduling somehow matches our > invariant. If not, that would be bad...)
I'm requesting education about UB. In 2.5 and master we have the following behaviors: * the low-priority thread (the servo thread) does not interrupt the high-priority thread (the base thread) * the high-priority thread (base thread) and the low-priority thread (servo thread) do not run concurrently on different processors RTAI and libpth provide these behaviors. (This all made sense when computers had a single processor, and it probably does not make sense now that computers have multiple processors, but that is not the discussion i want to have in this thread.) In UB there are four(?) new thread styles: xenomai-kernel, xenomai, rtpreempt, and posix. (That's in addition to the rtai thread style which is the same as the rtai thread style in 2.5 & master.) We know that posix threads do not preserve the scheduling behaviors above, this was revealed by the threads.0 test. I do not know if the remaining three thread styles preserve the scheduling behaviors, and if they do, what the mechanisms that implement this behavior are. John or Michael, can you illuminate the issue? -- Sebastian Kuzminsky ------------------------------------------------------------------------------ Subversion Kills Productivity. Get off Subversion & Make the Move to Perforce. With Perforce, you get hassle-free workflows. Merge that actually works. Faster operations. Version large binaries. Built-in WAN optimization and the freedom to use Git, Perforce or both. Make the move to Perforce. http://pubads.g.doubleclick.net/gampad/clk?id=122218951&iu=/4140/ostg.clktrk _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
