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Re: jiffies - Where does it get updated in the Kernel ?

Hi...
Hello,

I'm in the process of porting a new M68K based CPU arch to Linux
v2.6.20. I'm currently at the start_kernel() routine stuck in an
infinite loop inside of a call to calibrate_delay().

Maybe the timer chip isn't activated yet? 
The kernel is
spinning inside of while( ticks == jiffies ) in the following snippet
from init/calibrate.c:

printk(KERN_DEBUG "Calibrating delay loop... ");
while ((loops_per_jiffy <<= 1) != 0) {
    /* wait for "start of" clock tick */
    ticks = jiffies;
   while (ticks == jiffies)
       /* nothing */;
    /* Go .. */
    ticks = jiffies;
    __delay(loops_per_jiffy);
    ticks = jiffies - ticks;
    if (ticks)
        break;

My problem seems to be that the jiffies variable is not being updated.
It looks like jiffies is a common value in the kernel and it looks
like it gets updated somewhere. My question is where do I look in the
kernel to see how the jiffies variable gets updated?
I am x86 man, so I am not sure if it's applicable to all archs. Please see scheduler_tick() in kernel/sched.c Either it is updated directly by this function or one of its callees.


regards,

Mulyadi


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