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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * 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
- * Copyright (C) 2017-2018 SUSE, Frederic Weisbecker
- *
- */
- #include "sched.h"
- DEFINE_STATIC_KEY_FALSE(housekeeping_overridden);
- EXPORT_SYMBOL_GPL(housekeeping_overridden);
- static cpumask_var_t housekeeping_mask;
- static unsigned int housekeeping_flags;
- bool housekeeping_enabled(enum hk_flags flags)
- {
- return !!(housekeeping_flags & flags);
- }
- EXPORT_SYMBOL_GPL(housekeeping_enabled);
- int housekeeping_any_cpu(enum hk_flags flags)
- {
- int cpu;
- if (static_branch_unlikely(&housekeeping_overridden)) {
- if (housekeeping_flags & flags) {
- cpu = sched_numa_find_closest(housekeeping_mask, smp_processor_id());
- if (cpu < nr_cpu_ids)
- return cpu;
- return cpumask_any_and(housekeeping_mask, cpu_online_mask);
- }
- }
- return smp_processor_id();
- }
- EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
- const struct cpumask *housekeeping_cpumask(enum hk_flags flags)
- {
- if (static_branch_unlikely(&housekeeping_overridden))
- if (housekeeping_flags & flags)
- return housekeeping_mask;
- return cpu_possible_mask;
- }
- EXPORT_SYMBOL_GPL(housekeeping_cpumask);
- void housekeeping_affine(struct task_struct *t, enum hk_flags flags)
- {
- if (static_branch_unlikely(&housekeeping_overridden))
- if (housekeeping_flags & flags)
- set_cpus_allowed_ptr(t, housekeeping_mask);
- }
- EXPORT_SYMBOL_GPL(housekeeping_affine);
- bool housekeeping_test_cpu(int cpu, enum hk_flags flags)
- {
- if (static_branch_unlikely(&housekeeping_overridden))
- if (housekeeping_flags & flags)
- return cpumask_test_cpu(cpu, housekeeping_mask);
- return true;
- }
- EXPORT_SYMBOL_GPL(housekeeping_test_cpu);
- void __init housekeeping_init(void)
- {
- if (!housekeeping_flags)
- return;
- static_branch_enable(&housekeeping_overridden);
- if (housekeeping_flags & HK_FLAG_TICK)
- sched_tick_offload_init();
- /* We need at least one CPU to handle housekeeping work */
- WARN_ON_ONCE(cpumask_empty(housekeeping_mask));
- }
- static int __init housekeeping_setup(char *str, enum hk_flags flags)
- {
- cpumask_var_t non_housekeeping_mask;
- cpumask_var_t tmp;
- int err;
- alloc_bootmem_cpumask_var(&non_housekeeping_mask);
- err = cpulist_parse(str, non_housekeeping_mask);
- if (err < 0 || cpumask_last(non_housekeeping_mask) >= nr_cpu_ids) {
- pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n");
- free_bootmem_cpumask_var(non_housekeeping_mask);
- return 0;
- }
- alloc_bootmem_cpumask_var(&tmp);
- if (!housekeeping_flags) {
- alloc_bootmem_cpumask_var(&housekeeping_mask);
- cpumask_andnot(housekeeping_mask,
- cpu_possible_mask, non_housekeeping_mask);
- cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask);
- if (cpumask_empty(tmp)) {
- pr_warn("Housekeeping: must include one present CPU, "
- "using boot CPU:%d\n", smp_processor_id());
- __cpumask_set_cpu(smp_processor_id(), housekeeping_mask);
- __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);
- }
- } else {
- cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask);
- if (cpumask_empty(tmp))
- __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);
- cpumask_andnot(tmp, cpu_possible_mask, non_housekeeping_mask);
- if (!cpumask_equal(tmp, housekeeping_mask)) {
- pr_warn("Housekeeping: nohz_full= must match isolcpus=\n");
- free_bootmem_cpumask_var(tmp);
- free_bootmem_cpumask_var(non_housekeeping_mask);
- return 0;
- }
- }
- free_bootmem_cpumask_var(tmp);
- if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) {
- if (IS_ENABLED(CONFIG_NO_HZ_FULL)) {
- tick_nohz_full_setup(non_housekeeping_mask);
- } else {
- pr_warn("Housekeeping: nohz unsupported."
- " Build with CONFIG_NO_HZ_FULL\n");
- free_bootmem_cpumask_var(non_housekeeping_mask);
- return 0;
- }
- }
- housekeeping_flags |= flags;
- free_bootmem_cpumask_var(non_housekeeping_mask);
- return 1;
- }
- static int __init housekeeping_nohz_full_setup(char *str)
- {
- unsigned int flags;
- flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU |
- HK_FLAG_MISC | HK_FLAG_KTHREAD;
- return housekeeping_setup(str, flags);
- }
- __setup("nohz_full=", housekeeping_nohz_full_setup);
- static int __init housekeeping_isolcpus_setup(char *str)
- {
- unsigned int flags = 0;
- bool illegal = false;
- char *par;
- int len;
- while (isalpha(*str)) {
- if (!strncmp(str, "nohz,", 5)) {
- str += 5;
- flags |= HK_FLAG_TICK;
- continue;
- }
- if (!strncmp(str, "domain,", 7)) {
- str += 7;
- flags |= HK_FLAG_DOMAIN;
- continue;
- }
- if (!strncmp(str, "managed_irq,", 12)) {
- str += 12;
- flags |= HK_FLAG_MANAGED_IRQ;
- continue;
- }
- /*
- * Skip unknown sub-parameter and validate that it is not
- * containing an invalid character.
- */
- for (par = str, len = 0; *str && *str != ','; str++, len++) {
- if (!isalpha(*str) && *str != '_')
- illegal = true;
- }
- if (illegal) {
- pr_warn("isolcpus: Invalid flag %.*s\n", len, par);
- return 0;
- }
- pr_info("isolcpus: Skipped unknown flag %.*s\n", len, par);
- str++;
- }
- /* Default behaviour for isolcpus without flags */
- if (!flags)
- flags |= HK_FLAG_DOMAIN;
- return housekeeping_setup(str, flags);
- }
- __setup("isolcpus=", housekeeping_isolcpus_setup);
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