Hi Viresh, Thank you very much for your review and your suggestions.
On 02/21/2013 06:59 AM, Viresh Kumar wrote: > Sorry for this but i already have a patchset which has changed these files > to some extent. Can you please rebase over them? Actually my patchset > is already accepted, its just that rafael didn't wanted to have them for 3.9. > > http://git.linaro.org/gitweb?p=people/vireshk/linux.git;a=shortlog;h=refs/heads/cpufreq-for-3.10 No problem. I rebased the patch over your tree. > So, probably you just don't need this tunable: early_differential. > Rather just increase the frequency without doing this calculation: > > if (load_freq > od_tuners.up_threshold * policy->cur) { I agree with your suggestion. This is simpler approach. So, if the gradient is greater than grad_up_threshold we increase frequency immediately. i.e. if previous load was 10 and current load is 65 the gradient will be 55 (> grad_up_theshold) and we increase frequency >> + if (od_tuners.early_demand) { >> + if (load_freq > dbs_info->prev_load_freq) { > > && (load_freq < od_tuners.up_threshold * policy->cur) ?? In my opinion this is not necessary. If load_freq is greater, then we have to increase frequency in anyway. > >> +show_one(od, early_demand, early_demand); > > What about making other two tunables rw? > Of course. I added the grad_up_threshold. Following patch v2. Thanks again, Stratos ------------------------8<---------------------------------------------- Instead of checking only the absolute value of CPU load_freq to increase frequency, we detect forthcoming CPU load rise and increase frequency earlier. Every sampling rate, we calculate the gradient of load_freq. If it is too steep we assume that the load most probably will go over up_threshold in next iteration(s) and we increase frequency immediately. New tuners are introduced: - early_demand: to enable this functionality (disabled by default). - grad_up_threshold: over this gradient of load we will increase frequency immediately. Signed-off-by: Stratos Karafotis <strat...@semaphore.gr> --- drivers/cpufreq/cpufreq_governor.c | 1 + drivers/cpufreq/cpufreq_governor.h | 6 +++- drivers/cpufreq/cpufreq_ondemand.c | 72 ++++++++++++++++++++++++++++++++++---- 3 files changed, 72 insertions(+), 7 deletions(-) diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c index 7722505..e737aa9 100644 --- a/drivers/cpufreq/cpufreq_governor.c +++ b/drivers/cpufreq/cpufreq_governor.c @@ -322,6 +322,7 @@ int cpufreq_governor_dbs(struct cpufreq_policy *policy, } else { od_dbs_info->rate_mult = 1; od_dbs_info->sample_type = OD_NORMAL_SAMPLE; + od_dbs_info->prev_load_freq = 0; od_ops->powersave_bias_init_cpu(cpu); } diff --git a/drivers/cpufreq/cpufreq_governor.h b/drivers/cpufreq/cpufreq_governor.h index 6301790..c9a237a 100644 --- a/drivers/cpufreq/cpufreq_governor.h +++ b/drivers/cpufreq/cpufreq_governor.h @@ -96,6 +96,7 @@ struct od_cpu_dbs_info_s { unsigned int freq_hi_jiffies; unsigned int rate_mult; unsigned int sample_type:1; + unsigned int prev_load_freq; }; struct cs_cpu_dbs_info_s { @@ -114,6 +115,8 @@ struct od_dbs_tuners { unsigned int adj_up_threshold; unsigned int powersave_bias; unsigned int io_is_busy; + unsigned int grad_up_threshold; + unsigned int early_demand; }; struct cs_dbs_tuners { @@ -160,7 +163,8 @@ struct od_ops { void (*powersave_bias_init_cpu)(int cpu); unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy, unsigned int freq_next, unsigned int relation); - void (*freq_increase)(struct cpufreq_policy *p, unsigned int freq); + void (*freq_increase)(struct od_cpu_dbs_info_s *dbs_info, + struct cpufreq_policy *p, unsigned int freq); }; struct cs_ops { diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index c5fd794..4c948af 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -31,6 +31,7 @@ #define DEF_FREQUENCY_DOWN_DIFFERENTIAL (10) #define DEF_FREQUENCY_UP_THRESHOLD (80) #define DEF_SAMPLING_DOWN_FACTOR (1) +#define DEF_GRAD_UP_THRESHOLD (50) #define MAX_SAMPLING_DOWN_FACTOR (100000) #define MICRO_FREQUENCY_DOWN_DIFFERENTIAL (3) #define MICRO_FREQUENCY_UP_THRESHOLD (95) @@ -139,11 +140,16 @@ static void ondemand_powersave_bias_init(void) } } -static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq) +static void dbs_freq_increase(struct od_cpu_dbs_info_s *dbs_info, + struct cpufreq_policy *p, unsigned int freq) { struct dbs_data *dbs_data = p->governor_data; struct od_dbs_tuners *od_tuners = dbs_data->tuners; + /* If switching to max speed, apply sampling_down_factor */ + if (p->cur < p->max) + dbs_info->rate_mult = od_tuners->sampling_down_factor; + if (od_tuners->powersave_bias) freq = powersave_bias_target(p, freq, CPUFREQ_RELATION_H); else if (p->cur == p->max) @@ -168,16 +174,29 @@ static void od_check_cpu(int cpu, unsigned int load_freq) struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy; struct dbs_data *dbs_data = policy->governor_data; struct od_dbs_tuners *od_tuners = dbs_data->tuners; + unsigned int prev_load_freq; dbs_info->freq_lo = 0; + /* + * Calculate the gradient of load_freq. If it is too steep we assume + * that the load will go over up_threshold in next iteration(s) and + * we increase the frequency immediately + */ + if (od_tuners->early_demand) { + prev_load_freq = dbs_info->prev_load_freq; + dbs_info->prev_load_freq = load_freq; + + if (load_freq > prev_load_freq && (load_freq - prev_load_freq > + od_tuners->grad_up_threshold * policy->cur)) { + dbs_freq_increase(dbs_info, policy, policy->max); + return; + } + } + /* Check for frequency increase */ if (load_freq > od_tuners->up_threshold * policy->cur) { - /* If switching to max speed, apply sampling_down_factor */ - if (policy->cur < policy->max) - dbs_info->rate_mult = - od_tuners->sampling_down_factor; - dbs_freq_increase(policy, policy->max); + dbs_freq_increase(dbs_info, policy, policy->max); return; } @@ -445,12 +464,47 @@ static ssize_t store_powersave_bias(struct cpufreq_policy *policy, return count; } +static ssize_t store_grad_up_threshold(struct cpufreq_policy *policy, + const char *buf, size_t count) +{ + struct dbs_data *dbs_data = policy->governor_data; + struct od_dbs_tuners *od_tuners = dbs_data->tuners; + unsigned int input; + int ret; + ret = sscanf(buf, "%u", &input); + + if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || + input < MIN_FREQUENCY_UP_THRESHOLD) { + return -EINVAL; + } + + od_tuners->grad_up_threshold = input; + return count; +} + +static ssize_t store_early_demand(struct cpufreq_policy *policy, + const char *buf, size_t count) +{ + struct dbs_data *dbs_data = policy->governor_data; + struct od_dbs_tuners *od_tuners = dbs_data->tuners; + unsigned int input; + int ret; + + ret = sscanf(buf, "%u", &input); + if (ret != 1) + return -EINVAL; + od_tuners->early_demand = !!input; + return count; +} + show_one(od, sampling_rate, sampling_rate); show_one(od, io_is_busy, io_is_busy); show_one(od, up_threshold, up_threshold); show_one(od, sampling_down_factor, sampling_down_factor); show_one(od, ignore_nice, ignore_nice); show_one(od, powersave_bias, powersave_bias); +show_one(od, grad_up_threshold, grad_up_threshold); +show_one(od, early_demand, early_demand); declare_show_sampling_rate_min(); cpufreq_freq_attr_rw(sampling_rate); @@ -459,6 +513,8 @@ cpufreq_freq_attr_rw(up_threshold); cpufreq_freq_attr_rw(sampling_down_factor); cpufreq_freq_attr_rw(ignore_nice); cpufreq_freq_attr_rw(powersave_bias); +cpufreq_freq_attr_rw(grad_up_threshold); +cpufreq_freq_attr_rw(early_demand); cpufreq_freq_attr_ro(sampling_rate_min); static struct attribute *dbs_attributes[] = { @@ -469,6 +525,8 @@ static struct attribute *dbs_attributes[] = { &ignore_nice.attr, &powersave_bias.attr, &io_is_busy.attr, + &grad_up_threshold.attr, + &early_demand.attr, NULL }; @@ -516,9 +574,11 @@ static int od_init(struct dbs_data *dbs_data) } tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR; + tuners->grad_up_threshold = DEF_GRAD_UP_THRESHOLD; tuners->ignore_nice = 0; tuners->powersave_bias = 0; tuners->io_is_busy = should_io_be_busy(); + tuners->early_demand = 0; dbs_data->tuners = tuners; mutex_init(&dbs_data->mutex); -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
