From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: [PATCH RFC] cpuidle/drivers/menu: Remove get_loadavg in the performance multiplier Date: Tue, 25 Sep 2018 11:38:44 +0200 Message-ID: <1537868328-13405-1-git-send-email-daniel.lezcano@linaro.org> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: rafael@kernel.org Cc: linux-pm@vger.kernel.org, Todd Kjos , Joel Fernandes , Colin Cross , "Rafael J. Wysocki" , "Peter Zijlstra (Intel)" , Ramesh Thomas , Alex Shi , open list List-Id: linux-pm@vger.kernel.org The function get_loadavg() returns almost always zero. To be more precise, statistically speaking for a total of 1023379 times passing to the function, the load is equal to zero 1020728 times, greater than 100, 610 times, the remaining is between 0 and 5. I'm putting in question this metric. Is it worth to keep it? Cc: Todd Kjos Cc: Joel Fernandes Cc: Colin Cross Signed-off-by: Daniel Lezcano --- drivers/cpuidle/governors/menu.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index e26a409..d939b8e 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -173,18 +173,10 @@ static inline int which_bucket(unsigned int duration, unsigned long nr_iowaiters * to be, the higher this multiplier, and thus the higher * the barrier to go to an expensive C state. */ -static inline int performance_multiplier(unsigned long nr_iowaiters, unsigned long load) +static inline int performance_multiplier(unsigned long nr_iowaiters) { - int mult = 1; - - /* for higher loadavg, we are more reluctant */ - - mult += 2 * get_loadavg(load); - /* for IO wait tasks (per cpu!) we add 5x each */ - mult += 10 * nr_iowaiters; - - return mult; + return 1 + 10 * nr_iowaiters; } static DEFINE_PER_CPU(struct menu_device, menu_devices); @@ -359,7 +351,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, * Use the performance multiplier and the user-configurable * latency_req to determine the maximum exit latency. */ - interactivity_req = data->predicted_us / performance_multiplier(nr_iowaiters, cpu_load); + interactivity_req = data->predicted_us / + performance_multiplier(nr_iowaiters); if (latency_req > interactivity_req) latency_req = interactivity_req; } -- 2.7.4