• KOSAKI Motohiro's avatar
    vmscan: implement swap token priority aging · d7911ef3
    KOSAKI Motohiro authored
    
    
    While testing for memcg aware swap token, I observed a swap token was
    often grabbed an intermittent running process (eg init, auditd) and they
    never release a token.
    
    Why?
    
    Some processes (eg init, auditd, audispd) wake up when a process exiting.
    And swap token can be get first page-in process when a process exiting
    makes no swap token owner.  Thus such above intermittent running process
    often get a token.
    
    And currently, swap token priority is only decreased at page fault path.
    Then, if the process sleep immediately after to grab swap token, the swap
    token priority never be decreased.  That's obviously undesirable.
    
    This patch implement very poor (and lightweight) priority aging.  It only
    be affect to the above corner case and doesn't change swap tendency
    workload performance (eg multi process qsbench load)
    Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
    Reviewed-by: default avatarRik van Riel <riel@redhat.com>
    Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu...
    d7911ef3
thrash.c 3.34 KB