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cpufreq: Move scheduler-related code to the sched directory

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Create cpufreq.c under kernel/sched/ and move the cpufreq code
related to the scheduler to that file and to sched.h.

Redefine cpufreq_update_util() as a static inline function to avoid
function calls at its call sites in the scheduler code (as suggested
by Peter Zijlstra).

Also move the definition of struct update_util_data and declaration
of cpufreq_set_update_util_data() from include/linux/cpufreq.h to
include/linux/sched.h.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
This commit is contained in:
Rafael J. Wysocki
2016-03-10 20:44:47 +01:00
parent 08f511fd41
commit adaf9fcd13
7 changed files with 96 additions and 88 deletions
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53
drivers/cpufreq/cpufreq.c
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@@ -103,59 +103,6 @@ static struct cpufreq_driver *cpufreq_driver;
static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
static DEFINE_RWLOCK(cpufreq_driver_lock);
static DEFINE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
/**
* cpufreq_set_update_util_data - Populate the CPU's update_util_data pointer.
* @cpu: The CPU to set the pointer for.
* @data: New pointer value.
*
* Set and publish the update_util_data pointer for the given CPU. That pointer
* points to a struct update_util_data object containing a callback function
* to call from cpufreq_update_util(). That function will be called from an RCU
* read-side critical section, so it must not sleep.
*
* Callers must use RCU-sched callbacks to free any memory that might be
* accessed via the old update_util_data pointer or invoke synchronize_sched()
* right after this function to avoid use-after-free.
*/
void cpufreq_set_update_util_data(int cpu, struct update_util_data *data)
{
if (WARN_ON(data && !data->func))
return;
rcu_assign_pointer(per_cpu(cpufreq_update_util_data, cpu), data);
}
EXPORT_SYMBOL_GPL(cpufreq_set_update_util_data);
/**
* cpufreq_update_util - Take a note about CPU utilization changes.
* @time: Current time.
* @util: Current utilization.
* @max: Utilization ceiling.
*
* This function is called by the scheduler on every invocation of
* update_load_avg() on the CPU whose utilization is being updated.
*
* It can only be called from RCU-sched read-side critical sections.
*/
void cpufreq_update_util(u64 time, unsigned long util, unsigned long max)
{
struct update_util_data *data;
#ifdef CONFIG_LOCKDEP
WARN_ON(debug_locks && !rcu_read_lock_sched_held());
#endif
data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data));
/*
* If this isn't inside of an RCU-sched read-side critical section, data
* may become NULL after the check below.
*/
if (data)
data->func(data, time, util, max);
}
/* Flag to suspend/resume CPUFreq governors */
static bool cpufreq_suspended;