linux/kernel/sched/cpufreq.c
Rafael J. Wysocki adaf9fcd13 cpufreq: Move scheduler-related code to the sched directory
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>
2016-03-10 20:44:47 +01:00

38 lines
1.3 KiB
C

/*
* Scheduler code and data structures related to cpufreq.
*
* Copyright (C) 2016, Intel Corporation
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include "sched.h"
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);