Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754750AbaJWJC0 (ORCPT ); Thu, 23 Oct 2014 05:02:26 -0400 Received: from mail-wi0-f178.google.com ([209.85.212.178]:52296 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754585AbaJWJBb (ORCPT ); Thu, 23 Oct 2014 05:01:31 -0400 From: Daniel Lezcano To: rjw@rjwysocki.net Cc: nicolas.pitre@linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, peterz@infradead.org, linaro-kernel@lists.linaro.org, patches@linaro.org Subject: [PATCH V2 5/5] cpuidle: menu: Move the update function before its declaration Date: Thu, 23 Oct 2014 11:01:21 +0200 Message-Id: <1414054881-17713-5-git-send-email-daniel.lezcano@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1414054881-17713-1-git-send-email-daniel.lezcano@linaro.org> References: <1414054881-17713-1-git-send-email-daniel.lezcano@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to prevent a pointless forward declaration, just move the function at the beginning of the file. This patch does not change the behavior of the governor, it is just code reordering. Signed-off-by: Daniel Lezcano --- drivers/cpuidle/governors/menu.c | 149 +++++++++++++++++++-------------------- 1 file changed, 74 insertions(+), 75 deletions(-) diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index 6ae8390..0ac76b1 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -184,7 +184,6 @@ static inline int performance_multiplier(unsigned long nr_iowaiters, unsigned lo static DEFINE_PER_CPU(struct menu_device, menu_devices); -static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev); /* This implements DIV_ROUND_CLOSEST but avoids 64 bit division */ static u64 div_round64(u64 dividend, u32 divisor) @@ -192,6 +191,80 @@ static u64 div_round64(u64 dividend, u32 divisor) return div_u64(dividend + (divisor / 2), divisor); } +/** + * menu_update - attempts to guess what happened after entry + * @drv: cpuidle driver containing state data + * @dev: the CPU + */ +static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) +{ + struct menu_device *data = &__get_cpu_var(menu_devices); + int last_idx = data->last_state_idx; + struct cpuidle_state *target = &drv->states[last_idx]; + unsigned int measured_us; + unsigned int new_factor; + + /* + * Try to figure out how much time passed between entry to low + * power state and occurrence of the wakeup event. + * + * If the entered idle state didn't support residency measurements, + * we are basically lost in the dark how much time passed. + * As a compromise, assume we slept for the whole expected time. + * + * Any measured amount of time will include the exit latency. + * Since we are interested in when the wakeup begun, not when it + * was completed, we must subtract the exit latency. However, if + * the measured amount of time is less than the exit latency, + * assume the state was never reached and the exit latency is 0. + */ + if (unlikely(!(target->flags & CPUIDLE_FLAG_TIME_VALID))) { + /* Use timer value as is */ + measured_us = data->next_timer_us; + + } else { + /* Use measured value */ + measured_us = cpuidle_get_last_residency(dev); + + /* Deduct exit latency */ + if (measured_us > target->exit_latency) + measured_us -= target->exit_latency; + + /* Make sure our coefficients do not exceed unity */ + if (measured_us > data->next_timer_us) + measured_us = data->next_timer_us; + } + + /* Update our correction ratio */ + new_factor = data->correction_factor[data->bucket]; + new_factor -= new_factor / DECAY; + + if (data->next_timer_us > 0 && measured_us < MAX_INTERESTING) + new_factor += RESOLUTION * measured_us / data->next_timer_us; + else + /* + * we were idle so long that we count it as a perfect + * prediction + */ + new_factor += RESOLUTION; + + /* + * We don't want 0 as factor; we always want at least + * a tiny bit of estimated time. Fortunately, due to rounding, + * new_factor will stay nonzero regardless of measured_us values + * and the compiler can eliminate this test as long as DECAY > 1. + */ + if (DECAY == 1 && unlikely(new_factor == 0)) + new_factor = 1; + + data->correction_factor[data->bucket] = new_factor; + + /* update the repeating-pattern data */ + data->intervals[data->interval_ptr++] = measured_us; + if (data->interval_ptr >= INTERVALS) + data->interval_ptr = 0; +} + /* * Try detecting repeating patterns by keeping track of the last 8 * intervals, and checking if the standard deviation of that set @@ -378,80 +451,6 @@ static void menu_reflect(struct cpuidle_device *dev, int index) } /** - * menu_update - attempts to guess what happened after entry - * @drv: cpuidle driver containing state data - * @dev: the CPU - */ -static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) -{ - struct menu_device *data = &__get_cpu_var(menu_devices); - int last_idx = data->last_state_idx; - struct cpuidle_state *target = &drv->states[last_idx]; - unsigned int measured_us; - unsigned int new_factor; - - /* - * Try to figure out how much time passed between entry to low - * power state and occurrence of the wakeup event. - * - * If the entered idle state didn't support residency measurements, - * we are basically lost in the dark how much time passed. - * As a compromise, assume we slept for the whole expected time. - * - * Any measured amount of time will include the exit latency. - * Since we are interested in when the wakeup begun, not when it - * was completed, we must subtract the exit latency. However, if - * the measured amount of time is less than the exit latency, - * assume the state was never reached and the exit latency is 0. - */ - if (unlikely(!(target->flags & CPUIDLE_FLAG_TIME_VALID))) { - /* Use timer value as is */ - measured_us = data->next_timer_us; - - } else { - /* Use measured value */ - measured_us = cpuidle_get_last_residency(dev); - - /* Deduct exit latency */ - if (measured_us > target->exit_latency) - measured_us -= target->exit_latency; - - /* Make sure our coefficients do not exceed unity */ - if (measured_us > data->next_timer_us) - measured_us = data->next_timer_us; - } - - /* Update our correction ratio */ - new_factor = data->correction_factor[data->bucket]; - new_factor -= new_factor / DECAY; - - if (data->next_timer_us > 0 && measured_us < MAX_INTERESTING) - new_factor += RESOLUTION * measured_us / data->next_timer_us; - else - /* - * we were idle so long that we count it as a perfect - * prediction - */ - new_factor += RESOLUTION; - - /* - * We don't want 0 as factor; we always want at least - * a tiny bit of estimated time. Fortunately, due to rounding, - * new_factor will stay nonzero regardless of measured_us values - * and the compiler can eliminate this test as long as DECAY > 1. - */ - if (DECAY == 1 && unlikely(new_factor == 0)) - new_factor = 1; - - data->correction_factor[data->bucket] = new_factor; - - /* update the repeating-pattern data */ - data->intervals[data->interval_ptr++] = measured_us; - if (data->interval_ptr >= INTERVALS) - data->interval_ptr = 0; -} - -/** * menu_enable_device - scans a CPU's states and does setup * @drv: cpuidle driver * @dev: the CPU -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/