3.5.     73

if(nice_value < value){
ret = setpriority(which,pid,value);

}
//. . .

  3.1      .
       10,  -
  10.   ,   
which  who (.  ).  which  
,        .

PRIO_PROCESS  
PRIO_PGRP     
PRIO_USER    

     which  who  -
  (id) ,     .
  3.1  which   PRIO_PROCESS.  -
 3.1  who   0,     .
 value   setpriority ()    
   ,    . 
   Linux      -20  19.  -
 3.1     10,    
  10.     nice(), , 
 setpriority (),     ,
  ,      .

    ,    -
     .    
getpriority()     ,   -
   setpriority ()   0.     
  -1.   -1     -
   .  ,      
 getpriority (),      errno.

3.5.  

    ,   
    .      -
       , -
   . -     -
,        (..  -
     : ,
  "").      -
,  ,    ( ) 
 ,        .

     -    -
,      ,    .
 ()     .