.      jiffies  ,  
1000,  ,         .   -
         HZ,   -
 .

HZ           /*   */
(2*HZ)        /*   */
(HZ/2)        /*  */
(HZ/100)      /* 10  */
(2*HZ/100)    /* 20  */

 HZ    <asm/param.h>.    
  10, "   ".

  

         
 . ,     -
 86,   , ,      4 -
.      86,     -
    .    
  !  . 19.4     
    .

 19.4.	  	  
 	 PAGE	SHIFT  PAGE SIZE
alpha	13	8 
arm	12,14,15	4, 16, 32
cris	13	8 
h8300	12	4 
i386	12	4 
ia64	12, 13,14,16	4 , 8 , 32 , 64 
m68k	12, 13	4 , 8 
nri86knommu	12	4 
mips	12	4 
mips64	12	4 
parisc	12	4 
ppc	12	4 
ppc64	12	4 
s390	12	4 
sh	12	4 
spare	12, 13	4 , 8 
sparc64	13	8 
v850	12	4 
x8664	12	4 

402  19