• Morten Rasmussen's avatar
    sched: Disable wake_affine to broaden the scope of wakeup target cpus · 387e6491
    Morten Rasmussen authored
    SD_WAKE_AFFINE is currently set by default on all levels which means
    that wakeups are always handled inside the lowest level sched_domain.
    That means a tiny periodic task is very likely to stay on the cpu it was
    forked on forever. To save energy we need to revisit the task placement
    decision every now and again to ensure that we don't keep waking the
    same cpu if there are cheaper alternatives.
    One way is to simply disable wake_affine and rely on the fork/exec
    balancing mechanism (find_idlest_{group, cpu}). This is what this patch
    An alternative is to let the platform remove the SD_WAKE_AFFINE flag
    from lower levels to increase the search space for
    Signed-off-by: Morten Rasmussen's avatarMorten Rasmussen <morten.rasmussen@arm.com>