   .  ,    
     .     -
   ,      ,   
    . ,  -
         .  
  ,     -
 pdflush,    wb_kupdate ().   
  ,      dirty_expire centi-
secs    .     , 
  dirty_expire_centisecs  .   
pdflush          -
 ,    ,   .

        
/proc/sys/vm   sysctl.  . 15.1    -
 .

 15.1.     pdflush

 

dirty_background_ratio          ,   
pdflush     

dirty_expire_centisecs       ,    ,    -
     ,   
 pdflush       
  

dirty_ratio                       , 
   ,   -
    

dirty_writeback_centisecs     ,    ,  bdflush
      

laptop_mode                     ,    
  (.  )

  pdflush    mm/page-writeback.c  fs/
fs-writeback.c.

 

          
       .  
    ,     -
    .      -
  /proc/sys/vm/laptop_mode.      
 0    .   1    
  .

         
 .        ,
    ,  pdflush    
   -,     

338                                                                    15