The libelpthread caught my eye -- a "version of libpthread, optimized for operation in hard real time" (according to bing translator). And there's a paper in English about this: http://www.mcst.ru/doc/1107/PCS223.pdf
They also state that in realtime mode it's possible to set up different modes of external interrupt handling, "computation scheduling", "disk i/o" and "some other things", whatever that might mean. Kernel is modified to support realtime operation too.
The libelpthread caught my eye -- a "version of libpthread, optimized for operation in hard real time" (according to bing translator). And there's a paper in English about this: http://www.mcst.ru/doc/1107/PCS223.pdf