From 4bd4e42819c7b5b2d608b353f4d9a7717e586479 Mon Sep 17 00:00:00 2001 From: Stratos Karafotis Date: Wed, 6 Feb 2013 13:34:00 +0100 Subject: [PATCH] cpufreq: ondemand: Replace down_differential tuner with adj_up_threshold In order to avoid the calculation of up_threshold - down_differential every time that the frequency must be decreased, we replace the down_differential tuner with the adj_up_threshold which keeps the difference across multiple checks. Update the adj_up_threshold only when the up_theshold is also updated. Signed-off-by: Stratos Karafotis Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq_governor.h | 2 +- drivers/cpufreq/cpufreq_ondemand.c | 16 ++++++++++------ 2 files changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/cpufreq/cpufreq_governor.h b/drivers/cpufreq/cpufreq_governor.h index 16314b6..d2ac911 100644 --- a/drivers/cpufreq/cpufreq_governor.h +++ b/drivers/cpufreq/cpufreq_governor.h @@ -109,7 +109,7 @@ struct od_dbs_tuners { unsigned int sampling_rate; unsigned int sampling_down_factor; unsigned int up_threshold; - unsigned int down_differential; + unsigned int adj_up_threshold; unsigned int powersave_bias; unsigned int io_is_busy; }; diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index f38b8da..09b27ae 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -47,7 +47,8 @@ static struct cpufreq_governor cpufreq_gov_ondemand; static struct od_dbs_tuners od_tuners = { .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR, - .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL, + .adj_up_threshold = DEF_FREQUENCY_UP_THRESHOLD - + DEF_FREQUENCY_DOWN_DIFFERENTIAL, .ignore_nice = 0, .powersave_bias = 0, }; @@ -192,11 +193,9 @@ static void od_check_cpu(int cpu, unsigned int load_freq) * support the current CPU usage without triggering the up policy. To be * safe, we focus 10 points under the threshold. */ - if (load_freq < (od_tuners.up_threshold - od_tuners.down_differential) * - policy->cur) { + if (load_freq < od_tuners.adj_up_threshold * policy->cur) { unsigned int freq_next; - freq_next = load_freq / (od_tuners.up_threshold - - od_tuners.down_differential); + freq_next = load_freq / od_tuners.adj_up_threshold; /* No longer fully busy, reset rate_mult */ dbs_info->rate_mult = 1; @@ -359,6 +358,10 @@ static ssize_t store_up_threshold(struct kobject *a, struct attribute *b, input < MIN_FREQUENCY_UP_THRESHOLD) { return -EINVAL; } + /* Calculate the new adj_up_threshold */ + od_tuners.adj_up_threshold += input; + od_tuners.adj_up_threshold -= od_tuners.up_threshold; + od_tuners.up_threshold = input; return count; } @@ -515,7 +518,8 @@ static int __init cpufreq_gov_dbs_init(void) if (idle_time != -1ULL) { /* Idle micro accounting is supported. Use finer thresholds */ od_tuners.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD; - od_tuners.down_differential = MICRO_FREQUENCY_DOWN_DIFFERENTIAL; + od_tuners.adj_up_threshold = MICRO_FREQUENCY_UP_THRESHOLD - + MICRO_FREQUENCY_DOWN_DIFFERENTIAL; /* * In nohz/micro accounting case we set the minimum frequency * not depending on HZ, but fixed (very low). The deferred -- 2.7.4