From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leo Yan Subject: [PATCH v1 2/5] cpuidle: menu: Record tick delta value in struct menu_device Date: Mon, 13 Aug 2018 00:09:28 +0800 Message-ID: <1534090171-14464-3-git-send-email-leo.yan@linaro.org> References: <1534090171-14464-1-git-send-email-leo.yan@linaro.org> Return-path: In-Reply-To: <1534090171-14464-1-git-send-email-leo.yan@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: "Rafael J. Wysocki" , "Peter Zijlstra (Intel)" , Daniel Lezcano , Vincent Guittot , Ramesh Thomas , linux-kernel@vger.kernel.org, Linux PM Cc: Leo Yan List-Id: linux-pm@vger.kernel.org Since the tick delta is used in multiple places in menu_select(), it's better to use single one variable to record this value; furthermore, for more readable we can refactor the code to split a separate function to making decision for stopping tick, which also needs to use tick delta value as one metric for consideration. To achieve these purposes, this patch adds a new item 'tick_delta_us' in struct menu_device to record tick delta value. This patch also is a preparation for optimization stopping tick in sequential patches. Signed-off-by: Leo Yan --- drivers/cpuidle/governors/menu.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index b972db1..83618ab 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -124,6 +124,7 @@ struct menu_device { int tick_wakeup; unsigned int next_timer_us; + unsigned int tick_delta_us; unsigned int predicted_us; unsigned int bucket; unsigned int correction_factor[BUCKETS]; @@ -305,6 +306,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, /* determine the expected residency time, round up */ data->next_timer_us = ktime_to_us(tick_nohz_get_sleep_length(&delta_next)); + data->tick_delta_us = ktime_to_us(delta_next); get_iowait_load(&nr_iowaiters, &cpu_load); data->bucket = which_bucket(data->next_timer_us, nr_iowaiters); @@ -317,7 +319,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, * timer event for the idle state selection. */ if (tick_nohz_tick_stopped()) { - data->predicted_us = ktime_to_us(delta_next); + data->predicted_us = data->tick_delta_us; goto select; } @@ -400,11 +402,11 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, */ if (((drv->states[idx].flags & CPUIDLE_FLAG_POLLING) || data->predicted_us < TICK_USEC) && !tick_nohz_tick_stopped()) { - unsigned int delta_next_us = ktime_to_us(delta_next); *stop_tick = false; - if (idx > 0 && drv->states[idx].target_residency > delta_next_us) { + if (idx > 0 && + drv->states[idx].target_residency > data->tick_delta_us) { /* * The tick is not going to be stopped and the target * residency of the state to be returned is not within @@ -417,7 +419,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, continue; idx = i; - if (drv->states[i].target_residency <= delta_next_us) + if (drv->states[i].target_residency <= + data->tick_delta_us) break; } } -- 2.7.4