in_atomic
 

In kernel 2.6.8 file -- include/linux/hardirq:
Suppose kernel with SMP.

#define in_atomic ((preempt_count()&~PREEMPT_ACTIVE) != kernel_locked())

Qeustion1:
Why can this definition represent the atomic operation?
In my opinion,in_atomic is defined like this:
#define in_atomic ((preempt_count() &~PREEMPT_ACTIVE) ||kernel_locked()

Question2:
What's meaning of task_struct::lock_depth?

Qeustion3:
Additionally,can current task release CPU when lock_depth>=0?

these are questions about programming the linux kernel, and have no relation to Local Linux user meetings or other social events. please pick a more suitable forum to post in next time. thanks

I'm wrong....
 

Thank you for reminding me.
I just successully register in LUG,and post an unrelated quetion.Please delete it.
Sorry.....

This thread is more appropriate in Programming and has now been moved to that forum.