linux-stable/kernel/sched/cpufreq.c
Ingo Molnar 801c141955 sched/headers: Introduce kernel/sched/build_utility.c and build multiple .c files there
Collect all utility functionality source code files into a single kernel/sched/build_utility.c file,
via #include-ing the .c files:

    kernel/sched/clock.c
    kernel/sched/completion.c
    kernel/sched/loadavg.c
    kernel/sched/swait.c
    kernel/sched/wait_bit.c
    kernel/sched/wait.c

CONFIG_CPU_FREQ:
    kernel/sched/cpufreq.c

CONFIG_CPU_FREQ_GOV_SCHEDUTIL:
    kernel/sched/cpufreq_schedutil.c

CONFIG_CGROUP_CPUACCT:
    kernel/sched/cpuacct.c

CONFIG_SCHED_DEBUG:
    kernel/sched/debug.c

CONFIG_SCHEDSTATS:
    kernel/sched/stats.c

CONFIG_SMP:
   kernel/sched/cpupri.c
   kernel/sched/stop_task.c
   kernel/sched/topology.c

CONFIG_SCHED_CORE:
   kernel/sched/core_sched.c

CONFIG_PSI:
   kernel/sched/psi.c

CONFIG_MEMBARRIER:
   kernel/sched/membarrier.c

CONFIG_CPU_ISOLATION:
   kernel/sched/isolation.c

CONFIG_SCHED_AUTOGROUP:
   kernel/sched/autogroup.c

The goal is to amortize the 60+ KLOC header bloat from over a dozen build units into
a single build unit.

The build time of build_utility.c also roughly matches the build time of core.c and
fair.c - allowing better load-balancing of scheduler-only rebuilds.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
2022-02-23 10:58:33 +01:00

74 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Scheduler code and data structures related to cpufreq.
*
* Copyright (C) 2016, Intel Corporation
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*/
DEFINE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data);
/**
* cpufreq_add_update_util_hook - Populate the CPU's update_util_data pointer.
* @cpu: The CPU to set the pointer for.
* @data: New pointer value.
* @func: Callback function to set for the CPU.
*
* Set and publish the update_util_data pointer for the given CPU.
*
* The update_util_data pointer of @cpu is set to @data and the callback
* function pointer in the target struct update_util_data is set to @func.
* That function will be called by cpufreq_update_util() from RCU-sched
* read-side critical sections, so it must not sleep. @data will always be
* passed to it as the first argument which allows the function to get to the
* target update_util_data structure and its container.
*
* The update_util_data pointer of @cpu must be NULL when this function is
* called or it will WARN() and return with no effect.
*/
void cpufreq_add_update_util_hook(int cpu, struct update_util_data *data,
void (*func)(struct update_util_data *data, u64 time,
unsigned int flags))
{
if (WARN_ON(!data || !func))
return;
if (WARN_ON(per_cpu(cpufreq_update_util_data, cpu)))
return;
data->func = func;
rcu_assign_pointer(per_cpu(cpufreq_update_util_data, cpu), data);
}
EXPORT_SYMBOL_GPL(cpufreq_add_update_util_hook);
/**
* cpufreq_remove_update_util_hook - Clear the CPU's update_util_data pointer.
* @cpu: The CPU to clear the pointer for.
*
* Clear the update_util_data pointer for the given CPU.
*
* Callers must use RCU callbacks to free any memory that might be
* accessed via the old update_util_data pointer or invoke synchronize_rcu()
* right after this function to avoid use-after-free.
*/
void cpufreq_remove_update_util_hook(int cpu)
{
rcu_assign_pointer(per_cpu(cpufreq_update_util_data, cpu), NULL);
}
EXPORT_SYMBOL_GPL(cpufreq_remove_update_util_hook);
/**
* cpufreq_this_cpu_can_update - Check if cpufreq policy can be updated.
* @policy: cpufreq policy to check.
*
* Return 'true' if:
* - the local and remote CPUs share @policy,
* - dvfs_possible_from_any_cpu is set in @policy and the local CPU is not going
* offline (in which case it is not expected to run cpufreq updates any more).
*/
bool cpufreq_this_cpu_can_update(struct cpufreq_policy *policy)
{
return cpumask_test_cpu(smp_processor_id(), policy->cpus) ||
(policy->dvfs_possible_from_any_cpu &&
rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data)));
}