[PATCH 8/12] cpufreq: governor: Make governor private data per-policy

From: Rafael J. Wysocki
Date: Wed Feb 17 2016 - 20:41:29 EST

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

Some fields in struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s
are only used for a limited set of CPUs. Namely, if a policy is
shared between multiple CPUs, those fields will only be used for one
of them (policy->cpu). This means that they really are per-policy
rather than per-CPU and holding room for them in per-CPU data
structures is generally wasteful. Also moving those fields into
per-policy data structures will allow some significant simplifications
to be made going forward.

For this reason, introduce struct cs_policy_dbs_info and
struct od_policy_dbs_info to hold those fields. Define each of the
new structures as an extension of struct policy_dbs_info (such that
struct policy_dbs_info is embedded in each of them) and introduce
new ->alloc and ->free governor callbacks to allocate and free
those structures, respectively, such that ->alloc() will return
a pointer to the struct policy_dbs_info embedded in the allocated
data structure and ->free() will take that pointer as its argument.

With that, modify the code accessing the data fields in question
in per-CPU data objects to look for them in the new structures
via the struct policy_dbs_info pointer available to it and drop
them from struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/cpufreq_conservative.c | 34 ++++++++++++++++++++++--
drivers/cpufreq/cpufreq_governor.c | 7 ++---
drivers/cpufreq/cpufreq_governor.h | 9 +-----
drivers/cpufreq/cpufreq_ondemand.c | 45 ++++++++++++++++++++++++++-------
4 files changed, 71 insertions(+), 24 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq_conservative.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_conservative.c
+++ linux-pm/drivers/cpufreq/cpufreq_conservative.c
@@ -14,6 +14,17 @@
#include <linux/slab.h>
#include "cpufreq_governor.h"

+struct cs_policy_dbs_info {
+ struct policy_dbs_info policy_dbs;
+ unsigned int down_skip;
+ unsigned int requested_freq;
+};
+
+static inline struct cs_policy_dbs_info *to_dbs_info(struct policy_dbs_info *policy_dbs)
+{
+ return container_of(policy_dbs, struct cs_policy_dbs_info, policy_dbs);
+}
+
/* Conservative governor macros */
#define DEF_FREQUENCY_UP_THRESHOLD (80)
#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
@@ -48,8 +59,8 @@ static inline unsigned int get_freq_targ
*/
static unsigned int cs_dbs_timer(struct cpufreq_policy *policy)
{
- struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, policy->cpu);
struct policy_dbs_info *policy_dbs = policy->governor_data;
+ struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
struct dbs_data *dbs_data = policy_dbs->dbs_data;
struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
unsigned int load = dbs_update(policy);
@@ -238,6 +249,19 @@ static struct attribute *cs_attributes[]

/************************** sysfs end ************************/

+static struct policy_dbs_info *cs_alloc(void)
+{
+ struct cs_policy_dbs_info *dbs_info;
+
+ dbs_info = kzalloc(sizeof(*dbs_info), GFP_KERNEL);
+ return dbs_info ? &dbs_info->policy_dbs : NULL;
+}
+
+static void cs_free(struct policy_dbs_info *policy_dbs)
+{
+ kfree(to_dbs_info(policy_dbs));
+}
+
static int cs_init(struct dbs_data *dbs_data, bool notify)
{
struct cs_dbs_tuners *tuners;
@@ -276,7 +300,7 @@ static void cs_exit(struct dbs_data *dbs

static void cs_start(struct cpufreq_policy *policy)
{
- struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, policy->cpu);
+ struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);

dbs_info->down_skip = 0;
dbs_info->requested_freq = policy->cur;
@@ -294,6 +318,8 @@ static struct dbs_governor cs_dbs_gov =
.kobj_type = { .default_attrs = cs_attributes },
.get_cpu_cdbs = get_cpu_cdbs,
.gov_dbs_timer = cs_dbs_timer,
+ .alloc = cs_alloc,
+ .free = cs_free,
.init = cs_init,
.exit = cs_exit,
.start = cs_start,
@@ -305,9 +331,8 @@ static int dbs_cpufreq_notifier(struct n
void *data)
{
struct cpufreq_freqs *freq = data;
- struct cs_cpu_dbs_info_s *dbs_info =
- &per_cpu(cs_cpu_dbs_info, freq->cpu);
struct cpufreq_policy *policy = cpufreq_cpu_get_raw(freq->cpu);
+ struct cs_policy_dbs_info *dbs_info;

if (!policy)
return 0;
@@ -316,6 +341,7 @@ static int dbs_cpufreq_notifier(struct n
if (policy->governor != CPU_FREQ_GOV_CONSERVATIVE)
return 0;

+ dbs_info = to_dbs_info(policy->governor_data);
/*
* we only care if our internally tracked freq moves outside the 'valid'
* ranges of frequency available to us otherwise we do not change it
Index: linux-pm/drivers/cpufreq/cpufreq_governor.h
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_governor.h
+++ linux-pm/drivers/cpufreq/cpufreq_governor.h
@@ -157,17 +157,10 @@ struct cpu_dbs_info {

struct od_cpu_dbs_info_s {
struct cpu_dbs_info cdbs;
- struct cpufreq_frequency_table *freq_table;
- unsigned int freq_lo;
- unsigned int freq_lo_delay_us;
- unsigned int freq_hi_delay_us;
- unsigned int sample_type:1;
};

struct cs_cpu_dbs_info_s {
struct cpu_dbs_info cdbs;
- unsigned int down_skip;
- unsigned int requested_freq;
};

/* Per policy Governors sysfs tunables */
@@ -193,6 +186,8 @@ struct dbs_governor {

struct cpu_dbs_info *(*get_cpu_cdbs)(int cpu);
unsigned int (*gov_dbs_timer)(struct cpufreq_policy *policy);
+ struct policy_dbs_info *(*alloc)(void);
+ void (*free)(struct policy_dbs_info *policy_dbs);
int (*init)(struct dbs_data *dbs_data, bool notify);
void (*exit)(struct dbs_data *dbs_data, bool notify);
void (*start)(struct cpufreq_policy *policy);
Index: linux-pm/drivers/cpufreq/cpufreq_ondemand.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_ondemand.c
+++ linux-pm/drivers/cpufreq/cpufreq_ondemand.c
@@ -18,6 +18,20 @@
#include <linux/tick.h>
#include "cpufreq_governor.h"

+struct od_policy_dbs_info {
+ struct policy_dbs_info policy_dbs;
+ struct cpufreq_frequency_table *freq_table;
+ unsigned int freq_lo;
+ unsigned int freq_lo_delay_us;
+ unsigned int freq_hi_delay_us;
+ unsigned int sample_type:1;
+};
+
+static inline struct od_policy_dbs_info *to_dbs_info(struct policy_dbs_info *policy_dbs)
+{
+ return container_of(policy_dbs, struct od_policy_dbs_info, policy_dbs);
+}
+
/* On-demand governor macros */
#define DEF_FREQUENCY_UP_THRESHOLD (80)
#define DEF_SAMPLING_DOWN_FACTOR (1)
@@ -69,9 +83,8 @@ static unsigned int generic_powersave_bi
unsigned int freq_hi, freq_lo;
unsigned int index = 0;
unsigned int delay_hi_us;
- struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
- policy->cpu);
struct policy_dbs_info *policy_dbs = policy->governor_data;
+ struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
struct dbs_data *dbs_data = policy_dbs->dbs_data;
struct od_dbs_tuners *od_tuners = dbs_data->tuners;

@@ -114,10 +127,9 @@ static unsigned int generic_powersave_bi

static void ondemand_powersave_bias_init(struct cpufreq_policy *policy)
{
- unsigned int cpu = policy->cpu;
- struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
+ struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);

- dbs_info->freq_table = cpufreq_frequency_get_table(cpu);
+ dbs_info->freq_table = cpufreq_frequency_get_table(policy->cpu);
dbs_info->freq_lo = 0;
}

@@ -144,8 +156,8 @@ static void dbs_freq_increase(struct cpu
*/
static void od_update(struct cpufreq_policy *policy)
{
- struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, policy->cpu);
- struct policy_dbs_info *policy_dbs = dbs_info->cdbs.policy_dbs;
+ struct policy_dbs_info *policy_dbs = policy->governor_data;
+ struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
struct dbs_data *dbs_data = policy_dbs->dbs_data;
struct od_dbs_tuners *od_tuners = dbs_data->tuners;
unsigned int load = dbs_update(policy);
@@ -182,7 +194,7 @@ static unsigned int od_dbs_timer(struct
{
struct policy_dbs_info *policy_dbs = policy->governor_data;
struct dbs_data *dbs_data = policy_dbs->dbs_data;
- struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, policy->cpu);
+ struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
int sample_type = dbs_info->sample_type;

/* Common NORMAL_SAMPLE setup */
@@ -347,6 +359,19 @@ static struct attribute *od_attributes[]

/************************** sysfs end ************************/

+static struct policy_dbs_info *od_alloc(void)
+{
+ struct od_policy_dbs_info *dbs_info;
+
+ dbs_info = kzalloc(sizeof(*dbs_info), GFP_KERNEL);
+ return dbs_info ? &dbs_info->policy_dbs : NULL;
+}
+
+static void od_free(struct policy_dbs_info *policy_dbs)
+{
+ kfree(to_dbs_info(policy_dbs));
+}
+
static int od_init(struct dbs_data *dbs_data, bool notify)
{
struct od_dbs_tuners *tuners;
@@ -395,7 +420,7 @@ static void od_exit(struct dbs_data *dbs

static void od_start(struct cpufreq_policy *policy)
{
- struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, policy->cpu);
+ struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);

dbs_info->sample_type = OD_NORMAL_SAMPLE;
ondemand_powersave_bias_init(policy);
@@ -417,6 +442,8 @@ static struct dbs_governor od_dbs_gov =
.kobj_type = { .default_attrs = od_attributes },
.get_cpu_cdbs = get_cpu_cdbs,
.gov_dbs_timer = od_dbs_timer,
+ .alloc = od_alloc,
+ .free = od_free,
.init = od_init,
.exit = od_exit,
.start = od_start,
Index: linux-pm/drivers/cpufreq/cpufreq_governor.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_governor.c
+++ linux-pm/drivers/cpufreq/cpufreq_governor.c
@@ -385,8 +385,8 @@ static struct policy_dbs_info *alloc_pol
struct policy_dbs_info *policy_dbs;
int j;

- /* Allocate memory for the common information for policy->cpus */
- policy_dbs = kzalloc(sizeof(*policy_dbs), GFP_KERNEL);
+ /* Allocate memory for per-policy governor data. */
+ policy_dbs = gov->alloc();
if (!policy_dbs)
return NULL;

@@ -421,7 +421,7 @@ static void free_policy_dbs_info(struct
j_cdbs->policy_dbs = NULL;
j_cdbs->update_util.func = NULL;
}
- kfree(policy_dbs);
+ gov->free(policy_dbs);
}

static int cpufreq_governor_init(struct cpufreq_policy *policy)
@@ -582,7 +582,6 @@ static int cpufreq_governor_start(struct
static int cpufreq_governor_stop(struct cpufreq_policy *policy)
{
gov_cancel_work(policy);
-
return 0;
}

Next message: Rafael J. Wysocki: "[PATCH 7/12] cpufreq: ondemand: Rework the handling of powersave bias updates"
Previous message: Rafael J. Wysocki: "[PATCH 12/12] cpufreq: governor: Narrow down the dbs_data_mutex coverage"
In reply to: Viresh Kumar: "Re: [PATCH v2 12/12] cpufreq: governor: Narrow down the dbs_data_mutex coverage"
Next in thread: Viresh Kumar: "Re: [PATCH 8/12] cpufreq: governor: Make governor private data per-policy"
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