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authorViresh Kumar <viresh.kumar@linaro.org>2015-06-10 03:20:23 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-06-11 02:02:45 +0300
commit9591becbf226e3aa0f6c73494736e2c5ab14cc8d (patch)
tree045117d2fbb058e73f7679fc2b7140e9c3ec8f9d /drivers/cpufreq
parent3654c5cc810e9b1f7eadf19780d1bc5f37e1ae6e (diff)
downloadlinux-9591becbf226e3aa0f6c73494736e2c5ab14cc8d.tar.xz
cpufreq: Restart governor as soon as possible
__cpufreq_remove_dev_finish() is doing two things today: - Restarts the governor if some CPUs from concerned policy are still online. - Frees the policy if all CPUs are offline. The first task of restarting the governor can be moved to __cpufreq_remove_dev_prepare() to restart the governor early. There is no race between _prepare() and _finish() as they would be handling completely different cases. _finish() will only be required if we are going to free the policy and that has nothing to do with restarting the governor. Original-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq.c59
1 files changed, 26 insertions, 33 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 8b810071ddd2..c355ab656dfb 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1428,8 +1428,8 @@ nomem_out:
static int __cpufreq_remove_dev_prepare(struct device *dev,
struct subsys_interface *sif)
{
- unsigned int cpu = dev->id, cpus;
- int ret;
+ unsigned int cpu = dev->id;
+ int ret = 0;
struct cpufreq_policy *policy;
pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
@@ -1449,23 +1449,33 @@ static int __cpufreq_remove_dev_prepare(struct device *dev,
}
down_write(&policy->rwsem);
- cpus = cpumask_weight(policy->cpus);
+ cpumask_clear_cpu(cpu, policy->cpus);
- if (has_target() && cpus == 1)
- strncpy(policy->last_governor, policy->governor->name,
- CPUFREQ_NAME_LEN);
+ if (policy_is_inactive(policy)) {
+ if (has_target())
+ strncpy(policy->last_governor, policy->governor->name,
+ CPUFREQ_NAME_LEN);
+ } else if (cpu == policy->cpu) {
+ /* Nominate new CPU */
+ policy->cpu = cpumask_any(policy->cpus);
+ }
up_write(&policy->rwsem);
- if (cpu != policy->cpu)
- return 0;
+ /* Start governor again for active policy */
+ if (!policy_is_inactive(policy)) {
+ if (has_target()) {
+ ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
+ if (!ret)
+ ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
- if (cpus > 1)
- /* Nominate new CPU */
- update_policy_cpu(policy, cpumask_any_but(policy->cpus, cpu));
- else if (cpufreq_driver->stop_cpu)
+ if (ret)
+ pr_err("%s: Failed to start governor\n", __func__);
+ }
+ } else if (cpufreq_driver->stop_cpu) {
cpufreq_driver->stop_cpu(policy);
+ }
- return 0;
+ return ret;
}
static int __cpufreq_remove_dev_finish(struct device *dev,
@@ -1473,33 +1483,16 @@ static int __cpufreq_remove_dev_finish(struct device *dev,
{
unsigned int cpu = dev->id;
int ret;
- struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
+ struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
if (!policy) {
pr_debug("%s: No cpu_data found\n", __func__);
return -EINVAL;
}
- down_write(&policy->rwsem);
- cpumask_clear_cpu(cpu, policy->cpus);
- up_write(&policy->rwsem);
-
- /* Not the last cpu of policy, start governor again ? */
- if (!policy_is_inactive(policy)) {
- if (!has_target())
- return 0;
-
- ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
- if (!ret)
- ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
-
- if (ret) {
- pr_err("%s: Failed to start governor\n", __func__);
- return ret;
- }
-
+ /* Only proceed for inactive policies */
+ if (!policy_is_inactive(policy))
return 0;
- }
/* If cpu is last user of policy, free policy */
if (has_target()) {