[PATCH 2/12] cpufreq: governor: Move io_is_busy to struct dbs_data

From: Rafael J. Wysocki
Date: Wed Feb 17 2016 - 20:39:49 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

The io_is_busy governor tunable is only used by the ondemand governor
and is located in the ondemand-specific data structure, but it is
looked at by the common governor code that has to do ugly things to
get to that value, so move it to struct dbs_data and modify ondemand
accordingly.

Since the conservative governor never touches that field, it will
be always 0 for that governor and it won't have any effect on the
results of computations in that case.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/cpufreq_governor.c | 27 +++++++++------------------
drivers/cpufreq/cpufreq_governor.h | 2 +-
drivers/cpufreq/cpufreq_ondemand.c | 12 +++++-------
3 files changed, 15 insertions(+), 26 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq_governor.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_governor.c
+++ linux-pm/drivers/cpufreq/cpufreq_governor.c
@@ -137,10 +137,9 @@ unsigned int dbs_update(struct cpufreq_p
struct dbs_governor *gov = dbs_governor_of(policy);
struct policy_dbs_info *policy_dbs = policy->governor_data;
struct dbs_data *dbs_data = policy_dbs->dbs_data;
- struct od_dbs_tuners *od_tuners = dbs_data->tuners;
unsigned int ignore_nice = dbs_data->ignore_nice_load;
unsigned int max_load = 0;
- unsigned int sampling_rate, j;
+ unsigned int sampling_rate, io_busy, j;

/*
* Sometimes governors may use an additional multiplier to increase
@@ -149,6 +148,12 @@ unsigned int dbs_update(struct cpufreq_p
* conservative.
*/
sampling_rate = dbs_data->sampling_rate * policy_dbs->rate_mult;
+ /*
+ * For the purpose of ondemand, waiting for disk IO is an indication
+ * that you're performance critical, and not that the system is actually
+ * idle, so do not add the iowait time to the CPU idle time then.
+ */
+ io_busy = dbs_data->io_is_busy;

/* Get Absolute Load */
for_each_cpu(j, policy->cpus) {
@@ -156,18 +161,9 @@ unsigned int dbs_update(struct cpufreq_p
u64 cur_wall_time, cur_idle_time;
unsigned int idle_time, wall_time;
unsigned int load;
- int io_busy = 0;

j_cdbs = gov->get_cpu_cdbs(j);

- /*
- * For the purpose of ondemand, waiting for disk IO is
- * an indication that you're performance critical, and
- * not that the system is actually idle. So do not add
- * the iowait time to the cpu idle time.
- */
- if (gov->governor == GOV_ONDEMAND)
- io_busy = od_tuners->io_is_busy;
cur_idle_time = get_cpu_idle_time(j, &cur_wall_time, io_busy);

wall_time = cur_wall_time - j_cdbs->prev_cpu_wall;
@@ -522,7 +518,7 @@ static int cpufreq_governor_start(struct
struct policy_dbs_info *policy_dbs = policy->governor_data;
struct dbs_data *dbs_data = policy_dbs->dbs_data;
unsigned int sampling_rate, ignore_nice, j, cpu = policy->cpu;
- int io_busy = 0;
+ unsigned int io_busy;

if (!policy->cur)
return -EINVAL;
@@ -532,12 +528,7 @@ static int cpufreq_governor_start(struct

sampling_rate = dbs_data->sampling_rate;
ignore_nice = dbs_data->ignore_nice_load;
-
- if (gov->governor == GOV_ONDEMAND) {
- struct od_dbs_tuners *od_tuners = dbs_data->tuners;
-
- io_busy = od_tuners->io_is_busy;
- }
+ io_busy = dbs_data->io_is_busy;

for_each_cpu(j, policy->cpus) {
struct cpu_dbs_info *j_cdbs = gov->get_cpu_cdbs(j);
Index: linux-pm/drivers/cpufreq/cpufreq_governor.h
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_governor.h
+++ linux-pm/drivers/cpufreq/cpufreq_governor.h
@@ -71,6 +71,7 @@ struct dbs_data {
unsigned int sampling_rate;
unsigned int sampling_down_factor;
unsigned int up_threshold;
+ unsigned int io_is_busy;

struct kobject kobj;
struct list_head policy_dbs_list;
@@ -177,7 +178,6 @@ struct cs_cpu_dbs_info_s {
/* Per policy Governors sysfs tunables */
struct od_dbs_tuners {
unsigned int powersave_bias;
- unsigned int io_is_busy;
};

struct cs_dbs_tuners {
Index: linux-pm/drivers/cpufreq/cpufreq_ondemand.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_ondemand.c
+++ linux-pm/drivers/cpufreq/cpufreq_ondemand.c
@@ -220,7 +220,6 @@ static struct dbs_governor od_dbs_gov;
static ssize_t store_io_is_busy(struct dbs_data *dbs_data, const char *buf,
size_t count)
{
- struct od_dbs_tuners *od_tuners = dbs_data->tuners;
unsigned int input;
int ret;
unsigned int j;
@@ -228,14 +227,14 @@ static ssize_t store_io_is_busy(struct d
ret = sscanf(buf, "%u", &input);
if (ret != 1)
return -EINVAL;
- od_tuners->io_is_busy = !!input;
+ dbs_data->io_is_busy = !!input;

/* we need to re-evaluate prev_cpu_idle */
for_each_online_cpu(j) {
struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
j);
dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
- &dbs_info->cdbs.prev_cpu_wall, od_tuners->io_is_busy);
+ &dbs_info->cdbs.prev_cpu_wall, dbs_data->io_is_busy);
}
return count;
}
@@ -286,7 +285,6 @@ static ssize_t store_sampling_down_facto
static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data,
const char *buf, size_t count)
{
- struct od_dbs_tuners *od_tuners = dbs_data->tuners;
unsigned int input;
int ret;

@@ -309,7 +307,7 @@ static ssize_t store_ignore_nice_load(st
struct od_cpu_dbs_info_s *dbs_info;
dbs_info = &per_cpu(od_cpu_dbs_info, j);
dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
- &dbs_info->cdbs.prev_cpu_wall, od_tuners->io_is_busy);
+ &dbs_info->cdbs.prev_cpu_wall, dbs_data->io_is_busy);
if (dbs_data->ignore_nice_load)
dbs_info->cdbs.prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
@@ -342,7 +340,7 @@ gov_show_one_common(up_threshold);
gov_show_one_common(sampling_down_factor);
gov_show_one_common(ignore_nice_load);
gov_show_one_common(min_sampling_rate);
-gov_show_one(od, io_is_busy);
+gov_show_one_common(io_is_busy);
gov_show_one(od, powersave_bias);

gov_attr_rw(sampling_rate);
@@ -401,7 +399,7 @@ static int od_init(struct dbs_data *dbs_
dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
dbs_data->ignore_nice_load = 0;
tuners->powersave_bias = default_powersave_bias;
- tuners->io_is_busy = should_io_be_busy();
+ dbs_data->io_is_busy = should_io_be_busy();

dbs_data->tuners = tuners;
return 0;