• Christoph Lameter's avatar
    VM statistics: Make timer deferrable · 39bf6270
    Christoph Lameter authored
    VM statistics updates do not matter if the kernel is in idle powersaving
    mode.  So allow the timer to be deferred.
    It would be better though if we could switch the timer between deferrable
    and nondeferrable based on differentials present.  The timer would start
    out nondeferrable and if we find that there were no updates in the last
    statistics interval then we would switch the timer to deferrable.  If the
    timer later finds again that there are differentials then go to
    nondeferrable again.
    And yet another way would be to run the timer shortly before going to idle?
    The solution here means that the VM counters may be slightly off during
    idle since differentials may be still pending while the timer is deferred.
    Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>