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Date: Wed, 5 Jun 2013 14:34:33 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: rjw@...k.pl
Cc: linaro-kernel@...ts.linaro.org, patches@...aro.org,
cpufreq@...r.kernel.org, linux-pm@...r.kernel.org,
linux-kernel@...r.kernel.org, robin.randhawa@....com,
Steve.Bannister@....com, Liviu.Dudau@....com,
charles.garcia-tobin@....com, arvind.chauhan@....com,
chenxg.marvell@...il.com, Viresh Kumar <viresh.kumar@...aro.org>
Subject: [PATCH] cpufreq: userspace: Simplify governor
Userspace governor has got more code than what it needs for its functioning.
Lets simplify it.
Over that it will fix issues in cpufreq_governor_userspace(), which isn't doing
right things in START/STOP. It is working per-cpu currently whereas it just
required to manage policy->cpu.
Reported-by: Xiaoguang Chen <chenxg.marvell@...il.com>
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
@Rafael:
I don't know why this code was initially added. Please let me know if I am doing
something stupid.
Also, please apply it as a fix for 3.10 as it is broken recently in 3.9.
drivers/cpufreq/cpufreq_userspace.c | 108 ++++--------------------------------
1 file changed, 12 insertions(+), 96 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c
index bbeb9c0..5dc77b7 100644
--- a/drivers/cpufreq/cpufreq_userspace.c
+++ b/drivers/cpufreq/cpufreq_userspace.c
@@ -13,55 +13,13 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/smp.h>
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/interrupt.h>
#include <linux/cpufreq.h>
-#include <linux/cpu.h>
-#include <linux/types.h>
-#include <linux/fs.h>
-#include <linux/sysfs.h>
+#include <linux/init.h>
+#include <linux/module.h>
#include <linux/mutex.h>
-/**
- * A few values needed by the userspace governor
- */
-static DEFINE_PER_CPU(unsigned int, cpu_max_freq);
-static DEFINE_PER_CPU(unsigned int, cpu_min_freq);
-static DEFINE_PER_CPU(unsigned int, cpu_cur_freq); /* current CPU freq */
-static DEFINE_PER_CPU(unsigned int, cpu_set_freq); /* CPU freq desired by
- userspace */
static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
-
static DEFINE_MUTEX(userspace_mutex);
-static int cpus_using_userspace_governor;
-
-/* keep track of frequency transitions */
-static int
-userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
- void *data)
-{
- struct cpufreq_freqs *freq = data;
-
- if (!per_cpu(cpu_is_managed, freq->cpu))
- return 0;
-
- if (val == CPUFREQ_POSTCHANGE) {
- pr_debug("saving cpu_cur_freq of cpu %u to be %u kHz\n",
- freq->cpu, freq->new);
- per_cpu(cpu_cur_freq, freq->cpu) = freq->new;
- }
-
- return 0;
-}
-
-static struct notifier_block userspace_cpufreq_notifier_block = {
- .notifier_call = userspace_cpufreq_notifier
-};
-
/**
* cpufreq_set - set the CPU frequency
@@ -80,13 +38,6 @@ static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
if (!per_cpu(cpu_is_managed, policy->cpu))
goto err;
- per_cpu(cpu_set_freq, policy->cpu) = freq;
-
- if (freq < per_cpu(cpu_min_freq, policy->cpu))
- freq = per_cpu(cpu_min_freq, policy->cpu);
- if (freq > per_cpu(cpu_max_freq, policy->cpu))
- freq = per_cpu(cpu_max_freq, policy->cpu);
-
/*
* We're safe from concurrent calls to ->target() here
* as we hold the userspace_mutex lock. If we were calling
@@ -107,7 +58,7 @@ static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
static ssize_t show_speed(struct cpufreq_policy *policy, char *buf)
{
- return sprintf(buf, "%u\n", per_cpu(cpu_cur_freq, policy->cpu));
+ return sprintf(buf, "%u\n", policy->cur);
}
static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
@@ -119,66 +70,31 @@ static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
switch (event) {
case CPUFREQ_GOV_START:
BUG_ON(!policy->cur);
- mutex_lock(&userspace_mutex);
-
- if (cpus_using_userspace_governor == 0) {
- cpufreq_register_notifier(
- &userspace_cpufreq_notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
- }
- cpus_using_userspace_governor++;
+ pr_debug("started managing cpu %u\n", cpu);
+ mutex_lock(&userspace_mutex);
per_cpu(cpu_is_managed, cpu) = 1;
- per_cpu(cpu_min_freq, cpu) = policy->min;
- per_cpu(cpu_max_freq, cpu) = policy->max;
- per_cpu(cpu_cur_freq, cpu) = policy->cur;
- per_cpu(cpu_set_freq, cpu) = policy->cur;
- pr_debug("managing cpu %u started "
- "(%u - %u kHz, currently %u kHz)\n",
- cpu,
- per_cpu(cpu_min_freq, cpu),
- per_cpu(cpu_max_freq, cpu),
- per_cpu(cpu_cur_freq, cpu));
-
mutex_unlock(&userspace_mutex);
break;
case CPUFREQ_GOV_STOP:
- mutex_lock(&userspace_mutex);
- cpus_using_userspace_governor--;
- if (cpus_using_userspace_governor == 0) {
- cpufreq_unregister_notifier(
- &userspace_cpufreq_notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
- }
+ pr_debug("managing cpu %u stopped\n", cpu);
+ mutex_lock(&userspace_mutex);
per_cpu(cpu_is_managed, cpu) = 0;
- per_cpu(cpu_min_freq, cpu) = 0;
- per_cpu(cpu_max_freq, cpu) = 0;
- per_cpu(cpu_set_freq, cpu) = 0;
- pr_debug("managing cpu %u stopped\n", cpu);
mutex_unlock(&userspace_mutex);
break;
case CPUFREQ_GOV_LIMITS:
mutex_lock(&userspace_mutex);
- pr_debug("limit event for cpu %u: %u - %u kHz, "
- "currently %u kHz, last set to %u kHz\n",
+ pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz\n",
cpu, policy->min, policy->max,
- per_cpu(cpu_cur_freq, cpu),
- per_cpu(cpu_set_freq, cpu));
- if (policy->max < per_cpu(cpu_set_freq, cpu)) {
+ policy->cur);
+
+ if (policy->max < policy->cur)
__cpufreq_driver_target(policy, policy->max,
CPUFREQ_RELATION_H);
- } else if (policy->min > per_cpu(cpu_set_freq, cpu)) {
+ else if (policy->min > policy->cur)
__cpufreq_driver_target(policy, policy->min,
CPUFREQ_RELATION_L);
- } else {
- __cpufreq_driver_target(policy,
- per_cpu(cpu_set_freq, cpu),
- CPUFREQ_RELATION_L);
- }
- per_cpu(cpu_min_freq, cpu) = policy->min;
- per_cpu(cpu_max_freq, cpu) = policy->max;
- per_cpu(cpu_cur_freq, cpu) = policy->cur;
mutex_unlock(&userspace_mutex);
break;
}
--
1.7.12.rc2.18.g61b472e
--
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