• Ashwin Chaugule's avatar
    [PATCH] new scheme to preempt swap token · 7602bdf2
    Ashwin Chaugule authored
    The new swap token patches replace the current token traversal algo.  The old
    algo had a crude timeout parameter that was used to handover the token from
    one task to another.  This algo, transfers the token to the tasks that are in
    need of the token.  The urgency for the token is based on the number of times
    a task is required to swap-in pages.  Accordingly, the priority of a task is
    incremented if it has been badly affected due to swap-outs.  To ensure that
    the token doesnt bounce around rapidly, the token holders are given a priority
    boost.  The priority of tasks is also decremented, if their rate of swap-in's
    keeps reducing.  This way, the condition to check whether to pre-empt the swap
    token, is a matter of comparing two task's priority fields.
    [akpm@osdl.org: cleanups]
    Signed-off-by: default avatarAshwin Chaugule <ashwin.chaugule@celunite.com>
    Cc: Rik van Riel <riel@redhat.com>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
fork.c 42.4 KB