Things have just changed, with Novells release of SUSE Linux Enterprise Real Time (SLERT).
SLERT enables the use of Linux for real-time applications such as online stock trading, process control and operation, and telecommunications. SLERT does this by adding real-time technology from Concurrent Computer Corporation to SLES (SUSE Linux Enterprise Server) 10.
SLERT offers support for 32-bit and 64-bit processor architectures, including AMD Opteron and Intel Xeon, predictable interrupt response time of less than 30 microseconds, high-resolution timer support for enhanced scheduling, user-level control of simultaneous multithreading, and processor shielding.
In tightly-coupled symmetric multiprocessing systems, SLERT allows individual CPUs to be shielded from interrupt processing, daemons, bottom halves, and other Linux tasks.
Processor shielding provides a highly deterministic execution environment where interrupt response and the time it takes to execute a transaction can be guaranteed.