Good performance (hard realtime ??) on 2.6.16 patched with patch-2.6.16-rt29 from Ingo Molnar

[kernel]

Hello, 

I have tested 2.6.16 patched with 2.6.16-rt29 on two ordinary boxes (Dell 
PIII, 780 Mhz, IDE disks) connected back to back with ethernet cross at 
100Mbit, one broadcasting small udp messages @50Hz, the other receiving 
those messages. Distro Mandriva 2006.0, used .config from them. 

Conditions:
* Sending and receiving process @RT priority, FIFO, prio 99
* Sending box is almost idle, receiving box heavily loaded (cpu / mem).
* Watchdog/0 non RT (this setting is critical!)
* IRQ from network card on RT prio, rx thread from softirq-net-rx on RT prio 
(FIFO)
* posix_cpu_timer on RT
* kernel compiled without preemption debugging, complete realtime, 
scheduler@100Hz
* receiving process memory locked MCL_CURRENT|MCL_FUTURE
* Heavily loaded (continuously compiling kernel, with 100 jobs in parallel) 

I see following figures:
max latency 512 microseconds on receiving box, during 24 hours of heavily 
testing. 

** this looks like hard realtime, am I correct, or is this coincidence ? 

Thanks
Carl. 


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