c sytax

["shyam Burkule" <shyam.burkule@xxxxxxxxx>]

While reading linux 2.6.11 source code of mm ,i come across following c code...
 
 #define get_cpu_var(var)     (*( {preempt_disable(); &__get_cpu_var(var) ;}))

I am not understanding ,what this code means.....please explain....

-- 
Shyam
  "Born To Learn"