• Christoph Lameter's avatar
    [PATCH] zoned vm counters: split NR_ANON_PAGES off from NR_FILE_MAPPED · f3dbd344
    Christoph Lameter authored
    The current NR_FILE_MAPPED is used by zone reclaim and the dirty load
    calculation as the number of mapped pagecache pages.  However, that is not
    true.  NR_FILE_MAPPED includes the mapped anonymous pages.  This patch
    separates those and therefore allows an accurate tracking of the anonymous
    pages per zone.
    
    It then becomes possible to determine the number of unmapped pages per zone
    and we can avoid scanning for unmapped pages if there are none.
    
    Also it may now be possible to determine the mapped/unmapped ratio in
    get_dirty_limit.  Isnt the number of anonymous pages irrelevant in that
    calculation?
    
    Note that this will change the meaning of the number of mapped pages reported
    in /proc/vmstat /proc/meminfo and in the per node statistics.  This may affect
    user space tools that monitor these counters!  NR_FILE_MAPPED works like
    NR_FILE_DIRTY.  It is only valid for pagecache pages.
    Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
    Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    f3dbd344
page-writeback.c 23.2 KB