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    Subject[PATCH 6/6] cpuidle: menu: Move the latency_req == 0 special case check
    Date
    From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

    It is better to always update data->bucket before returning from
    menu_select() so as to prevent disturbing the wakeup statistics
    collected by the governor, so combine the latency_req == 0 special
    check with the more general check below.

    Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
    ---
    drivers/cpuidle/governors/menu.c | 8 +-------
    1 file changed, 1 insertion(+), 7 deletions(-)

    Index: linux-pm/drivers/cpuidle/governors/menu.c
    ===================================================================
    --- linux-pm.orig/drivers/cpuidle/governors/menu.c
    +++ linux-pm/drivers/cpuidle/governors/menu.c
    @@ -297,19 +297,13 @@ static int menu_select(struct cpuidle_dr
    data->needs_update = 0;
    }

    - /* Special case when user has set very strict latency requirement */
    - if (unlikely(latency_req == 0)) {
    - *stop_tick = false;
    - return 0;
    - }
    -
    /* determine the expected residency time, round up */
    data->next_timer_us = ktime_to_us(tick_nohz_get_sleep_length(&delta_next));

    get_iowait_load(&nr_iowaiters, &cpu_load);
    data->bucket = which_bucket(data->next_timer_us, nr_iowaiters);

    - if (unlikely(drv->state_count <= 1) ||
    + if (unlikely(drv->state_count <= 1 || latency_req == 0) ||
    ((data->next_timer_us < drv->states[1].target_residency ||
    latency_req < drv->states[1].exit_latency) &&
    !drv->states[0].disabled && !dev->states_usage[0].disable)) {
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      Last update: 2018-10-02 23:52    [W:6.351 / U:0.864 seconds]
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