 

   (   )     -
   (,    ),  -
      .   
    ,    
   ,      
.        
    jiffies,     .
   ,  100 ,    -
    10 !     
1000 ,      . ,  -
  ,       .

        -
 ,     <linux/delay.h>   
 jiffies.

void udelay(unsigned long usecs);

void mdelay(unsigned long msecs) ;

       
   .     
  .  ,     1000
,   1000000 .   
.

udelay(150); /*   150 us */

 udelay ()    ,   , 
      .  mdelay ()
    udelay ().     ,  
      (    
 BogoMIPS),  udelay     
 ,        -
 .

 BogoMIPS ,   !

 BogoMIPS      .    -
  BogoMIPS        
    udelay ()  mdelay ().    
   bogus ()  MIPS (million of instructions per second,  
 ).    ,        
 (    Pentium III   1).

Detected 1004.932 MHz processor.
Calibrating delay loop... 1990.65 BogoMIPS

  BogoMIPS -   ,    
   .     , 
     !      loops_per_
jiffy,       /proc/cpuinfo.

    229