From 1206aaac285904e3e3995eecbf4129b6555a8973 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Tue, 31 May 2005 19:03:48 -0700 Subject: [CPUFREQ] Allow ondemand stepping to be changed by user. Adds support so that the cpufreq change stepping is no longer fixed at 5% and can be changed dynamically by the user Signed-off-by: Alexander Clouter Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq_ondemand.c | 42 ++++++++++++++++++++++++++++++++------ 1 file changed, 36 insertions(+), 6 deletions(-) diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 6dc83808e590..056591612467 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -79,6 +79,7 @@ struct dbs_tuners { unsigned int up_threshold; unsigned int down_threshold; unsigned int ignore_nice; + unsigned int freq_step; }; static struct dbs_tuners dbs_tuners_ins = { @@ -117,6 +118,7 @@ show_one(sampling_down_factor, sampling_down_factor); show_one(up_threshold, up_threshold); show_one(down_threshold, down_threshold); show_one(ignore_nice, ignore_nice); +show_one(freq_step, freq_step); static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused, const char *buf, size_t count) @@ -235,6 +237,29 @@ static ssize_t store_ignore_nice(struct cpufreq_policy *policy, return count; } +static ssize_t store_freq_step(struct cpufreq_policy *policy, + const char *buf, size_t count) +{ + unsigned int input; + int ret; + + ret = sscanf (buf, "%u", &input); + + if ( ret != 1 ) + return -EINVAL; + + if ( input > 100 ) + input = 100; + + /* no need to test here if freq_step is zero as the user might actually + * want this, they would be crazy though :) */ + down(&dbs_sem); + dbs_tuners_ins.freq_step = input; + up(&dbs_sem); + + return count; +} + #define define_one_rw(_name) \ static struct freq_attr _name = \ __ATTR(_name, 0644, show_##_name, store_##_name) @@ -244,6 +269,7 @@ define_one_rw(sampling_down_factor); define_one_rw(up_threshold); define_one_rw(down_threshold); define_one_rw(ignore_nice); +define_one_rw(freq_step); static struct attribute * dbs_attributes[] = { &sampling_rate_max.attr, @@ -253,6 +279,7 @@ static struct attribute * dbs_attributes[] = { &up_threshold.attr, &down_threshold.attr, &ignore_nice.attr, + &freq_step.attr, NULL }; @@ -291,7 +318,7 @@ static void dbs_check_cpu(int cpu) * * Any frequency increase takes it to the maximum frequency. * Frequency reduction happens at minimum steps of - * 5% of max_frequency + * 5% (default) of max_frequency */ /* Check for frequency increase */ @@ -390,18 +417,20 @@ static void dbs_check_cpu(int cpu) usecs_to_jiffies(freq_down_sampling_rate); if (idle_ticks > down_idle_ticks ) { - /* if we are already at the lowest speed then break out early */ - if (policy->cur == policy->min) + /* if we are already at the lowest speed then break out early + * or if we 'cannot' reduce the speed as the user might want + * freq_step to be zero */ + if (policy->cur == policy->min || dbs_tuners_ins.freq_step == 0) return; - - freq_down_step = (5 * policy->max) / 100; + + freq_down_step = (dbs_tuners_ins.freq_step * policy->max) / 100; /* max freq cannot be less than 100. But who knows.... */ if (unlikely(freq_down_step == 0)) freq_down_step = 5; __cpufreq_driver_target(policy, - policy->cur - freq_down_step, + policy->cur - freq_down_step, CPUFREQ_RELATION_H); return; } @@ -486,6 +515,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; dbs_tuners_ins.sampling_rate = def_sampling_rate; dbs_tuners_ins.ignore_nice = 0; + dbs_tuners_ins.freq_step = 5; dbs_timer_init(); } -- cgit v1.2.3