73 строки
1.8 KiB
C
73 строки
1.8 KiB
C
/*
|
|
* Housekeeping management. Manage the targets for routine code that can run on
|
|
* any CPU: unbound workqueues, timers, kthreads and any offloadable work.
|
|
*
|
|
* Copyright (C) 2017 Red Hat, Inc., Frederic Weisbecker
|
|
*
|
|
*/
|
|
|
|
#include <linux/sched/isolation.h>
|
|
#include <linux/tick.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/static_key.h>
|
|
|
|
DEFINE_STATIC_KEY_FALSE(housekeeping_overriden);
|
|
EXPORT_SYMBOL_GPL(housekeeping_overriden);
|
|
static cpumask_var_t housekeeping_mask;
|
|
|
|
int housekeeping_any_cpu(void)
|
|
{
|
|
if (static_branch_unlikely(&housekeeping_overriden))
|
|
return cpumask_any_and(housekeeping_mask, cpu_online_mask);
|
|
|
|
return smp_processor_id();
|
|
}
|
|
EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
|
|
|
|
const struct cpumask *housekeeping_cpumask(void)
|
|
{
|
|
if (static_branch_unlikely(&housekeeping_overriden))
|
|
return housekeeping_mask;
|
|
|
|
return cpu_possible_mask;
|
|
}
|
|
EXPORT_SYMBOL_GPL(housekeeping_cpumask);
|
|
|
|
void housekeeping_affine(struct task_struct *t)
|
|
{
|
|
if (static_branch_unlikely(&housekeeping_overriden))
|
|
set_cpus_allowed_ptr(t, housekeeping_mask);
|
|
}
|
|
EXPORT_SYMBOL_GPL(housekeeping_affine);
|
|
|
|
bool housekeeping_test_cpu(int cpu)
|
|
{
|
|
if (static_branch_unlikely(&housekeeping_overriden))
|
|
return cpumask_test_cpu(cpu, housekeeping_mask);
|
|
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(housekeeping_test_cpu);
|
|
|
|
void __init housekeeping_init(void)
|
|
{
|
|
if (!tick_nohz_full_enabled())
|
|
return;
|
|
|
|
if (!alloc_cpumask_var(&housekeeping_mask, GFP_KERNEL)) {
|
|
WARN(1, "NO_HZ: Can't allocate not-full dynticks cpumask\n");
|
|
cpumask_clear(tick_nohz_full_mask);
|
|
tick_nohz_full_running = false;
|
|
return;
|
|
}
|
|
|
|
cpumask_andnot(housekeeping_mask,
|
|
cpu_possible_mask, tick_nohz_full_mask);
|
|
|
|
static_branch_enable(&housekeeping_overriden);
|
|
|
|
/* We need at least one CPU to handle housekeeping work */
|
|
WARN_ON_ONCE(cpumask_empty(housekeeping_mask));
|
|
}
|