dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

[PATCH] cpufreq_conservative: alternative initialise approach 

Venki, author of cpufreq_ondemand, came up with a neater way to remove the
initialiser code from the main loop of my code and out to the point when the
governor is actually initialised.

Not only does it look but it also feels cleaner, plus its simpler to
understand.  It also saves a bunch of pointless conditional statements in the
main loop.

Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
This commit is contained in:
Alexander Clouter 2006-03-22 10:00:18 +00:00 committed by Dominik Brodowski
parent 08a28e2e98
commit a159b82770
1 changed files with 18 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
drivers/cpufreq/cpufreq_conservative.c
View File

@ -65,6 +65,8 @@ struct cpu_dbs_info_s {
unsigned int prev_cpu_idle_up;
unsigned int prev_cpu_idle_down;
unsigned int enable;
unsigned int down_skip;
unsigned int requested_freq;
};
static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
@ -297,35 +299,12 @@ static void dbs_check_cpu(int cpu)
unsigned int tmp_idle_ticks, total_idle_ticks;
unsigned int freq_step;
unsigned int freq_down_sampling_rate;
static unsigned short down_skip[NR_CPUS];
static unsigned int requested_freq[NR_CPUS];
static unsigned int init_flag = NR_CPUS;
struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
struct cpufreq_policy *policy;
if (!this_dbs_info->enable)
return;
if ( init_flag != 0 ) {
for_each_cpu(init_flag) {
down_skip[init_flag] = 0;
/* I doubt a CPU exists with a freq of 0hz :) */
requested_freq[init_flag] = 0;
}
init_flag = 0;
}
/*
* If its a freshly initialised cpu we setup requested_freq. This
* check could be avoided if we did not care about a first time
* stunted increase in CPU speed when there is a load. I feel we
* should be initialising this to something. The removal of a CPU
* is not a problem, after a short time the CPU should settle down
* to a 'natural' frequency.
*/
if (requested_freq[cpu] == 0)
requested_freq[cpu] = this_dbs_info->cur_policy->cur;
policy = this_dbs_info->cur_policy;
/*
@ -360,12 +339,12 @@ static void dbs_check_cpu(int cpu)
usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
if (idle_ticks < up_idle_ticks) {
down_skip[cpu] = 0;
this_dbs_info->down_skip = 0;
this_dbs_info->prev_cpu_idle_down =
this_dbs_info->prev_cpu_idle_up;
/* if we are already at full speed then break out early */
if (requested_freq[cpu] == policy->max)
if (this_dbs_info->requested_freq == policy->max)
return;
freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100;
@ -374,18 +353,18 @@ static void dbs_check_cpu(int cpu)
if (unlikely(freq_step == 0))
freq_step = 5;
requested_freq[cpu] += freq_step;
if (requested_freq[cpu] > policy->max)
requested_freq[cpu] = policy->max;
this_dbs_info->requested_freq += freq_step;
if (this_dbs_info->requested_freq > policy->max)
this_dbs_info->requested_freq = policy->max;
__cpufreq_driver_target(policy, requested_freq[cpu],
__cpufreq_driver_target(policy, this_dbs_info->requested_freq,
CPUFREQ_RELATION_H);
return;
}
/* Check for frequency decrease */
down_skip[cpu]++;
if (down_skip[cpu] < dbs_tuners_ins.sampling_down_factor)
this_dbs_info->down_skip++;
if (this_dbs_info->down_skip < dbs_tuners_ins.sampling_down_factor)
return;
/* Check for frequency decrease */
@ -399,7 +378,7 @@ static void dbs_check_cpu(int cpu)
/* Scale idle ticks by 100 and compare with up and down ticks */
idle_ticks *= 100;
down_skip[cpu] = 0;
this_dbs_info->down_skip = 0;
freq_down_sampling_rate = dbs_tuners_ins.sampling_rate *
dbs_tuners_ins.sampling_down_factor;
@ -412,7 +391,7 @@ static void dbs_check_cpu(int cpu)
* or if we 'cannot' reduce the speed as the user might want
* freq_step to be zero
*/
if (requested_freq[cpu] == policy->min
if (this_dbs_info->requested_freq == policy->min
|| dbs_tuners_ins.freq_step == 0)
return;
@ -422,11 +401,11 @@ static void dbs_check_cpu(int cpu)
if (unlikely(freq_step == 0))
freq_step = 5;
requested_freq[cpu] -= freq_step;
if (requested_freq[cpu] < policy->min)
requested_freq[cpu] = policy->min;
this_dbs_info->requested_freq -= freq_step;
if (this_dbs_info->requested_freq < policy->min)
this_dbs_info->requested_freq = policy->min;
__cpufreq_driver_target(policy, requested_freq[cpu],
__cpufreq_driver_target(policy, this_dbs_info->requested_freq,
CPUFREQ_RELATION_H);
return;
}
@ -489,6 +468,8 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
= j_dbs_info->prev_cpu_idle_up;
}
this_dbs_info->enable = 1;
this_dbs_info->down_skip = 0;
this_dbs_info->requested_freq = policy->cur;
sysfs_create_group(&policy->kobj, &dbs_attr_group);
dbs_enable++;
/*