 ,        ,  
,       (
     4).

     ,   
 .

        
.

        , ..
      .    -
 ,        -
.  ,     ,   -
    .   "  "
       .

  : HZ

   ( , tick rate)  
      HZ,    
 .   HZ    -
  .   ,   
   HZ      .

      <asm/param.h>.  
    HZ,    1/HZ. , 
 include/asm-i386/param.h    i386  
  .

#define HZ 1000 /* internal kernel time frequency */

    i368    
 1000 , .. 1000    (     
).       
   100 .  . 10.1     -
         -
 .

     ,   HZ  
 .          , 
        
 .    Alpha  , 
      100 ,    
 ,       100 ,   -
  HZ.    HZ    
 .

    .   ,  -
    .       -
    .     
,         -
   .

    209