• Christoph Lameter's avatar
    [PATCH] ZVC: Overstep counters · a302eb4e
    Christoph Lameter authored
    Increments and decrements are usually grouped rather than mixed.  We can
    optimize the inc and dec functions for that case.
    Increment and decrement the counters by 50% more than the threshold in
    those cases and set the differential accordingly.  This decreases the need
    to update the atomic counters.
    The idea came originally from Andrew Morton.  The overstepping alone was
    sufficient to address the contention issue found when updating the global
    and the per zone counters from 160 processors.
    Also remove some code in dec_zone_page_state.
    Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
vmstat.c 13.1 KB