[rtl] What about atomicity?

["Kurt Rosenfeld" <kurtrosenfeld@hotmail.com>]

Hello everyone.  I am an RTL newbie.  I have read the documentation and 
I cannot figure out what happens under RTL to the critically-timed 
atomic functions in the Linux kernel.  It is clear that they are still 
atomic with respect to other Linux processes, but doesn't having an RTL 
process preempt something like a floppy disk driver screw the timing up.  

Also, while I am showing my confusion, can anyone tell me why in the 
...examples/parallel/sched_toggle.c the code has the variable "output" 
initialized to a 16-bit value and then fed to the 8-bit instruction 
outb?  Am I not seeing something subtle?


#define PERIOD 5 

RT_TASK mytask;
static int output = 0xffff;

void fun(int t) {


        while (1) {
        outb(output, LPT_PORT);
        output = ~output;
        rt_task_wait();
        }
}


thanks, kurt

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