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10#include "sched.h"
11
12DEFINE_STATIC_KEY_FALSE(housekeeping_overridden);
13EXPORT_SYMBOL_GPL(housekeeping_overridden);
14static cpumask_var_t housekeeping_mask;
15static unsigned int housekeeping_flags;
16
17bool housekeeping_enabled(enum hk_flags flags)
18{
19 return !!(housekeeping_flags & flags);
20}
21EXPORT_SYMBOL_GPL(housekeeping_enabled);
22
23int housekeeping_any_cpu(enum hk_flags flags)
24{
25 int cpu;
26
27 if (static_branch_unlikely(&housekeeping_overridden)) {
28 if (housekeeping_flags & flags) {
29 cpu = sched_numa_find_closest(housekeeping_mask, smp_processor_id());
30 if (cpu < nr_cpu_ids)
31 return cpu;
32
33 return cpumask_any_and(housekeeping_mask, cpu_online_mask);
34 }
35 }
36 return smp_processor_id();
37}
38EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
39
40const struct cpumask *housekeeping_cpumask(enum hk_flags flags)
41{
42 if (static_branch_unlikely(&housekeeping_overridden))
43 if (housekeeping_flags & flags)
44 return housekeeping_mask;
45 return cpu_possible_mask;
46}
47EXPORT_SYMBOL_GPL(housekeeping_cpumask);
48
49void housekeeping_affine(struct task_struct *t, enum hk_flags flags)
50{
51 if (static_branch_unlikely(&housekeeping_overridden))
52 if (housekeeping_flags & flags)
53 set_cpus_allowed_ptr(t, housekeeping_mask);
54}
55EXPORT_SYMBOL_GPL(housekeeping_affine);
56
57bool housekeeping_test_cpu(int cpu, enum hk_flags flags)
58{
59 if (static_branch_unlikely(&housekeeping_overridden))
60 if (housekeeping_flags & flags)
61 return cpumask_test_cpu(cpu, housekeeping_mask);
62 return true;
63}
64EXPORT_SYMBOL_GPL(housekeeping_test_cpu);
65
66void __init housekeeping_init(void)
67{
68 if (!housekeeping_flags)
69 return;
70
71 static_branch_enable(&housekeeping_overridden);
72
73 if (housekeeping_flags & HK_FLAG_TICK)
74 sched_tick_offload_init();
75
76
77 WARN_ON_ONCE(cpumask_empty(housekeeping_mask));
78}
79
80static int __init housekeeping_setup(char *str, enum hk_flags flags)
81{
82 cpumask_var_t non_housekeeping_mask;
83 cpumask_var_t tmp;
84
85 alloc_bootmem_cpumask_var(&non_housekeeping_mask);
86 if (cpulist_parse(str, non_housekeeping_mask) < 0) {
87 pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n");
88 free_bootmem_cpumask_var(non_housekeeping_mask);
89 return 0;
90 }
91
92 alloc_bootmem_cpumask_var(&tmp);
93 if (!housekeeping_flags) {
94 alloc_bootmem_cpumask_var(&housekeeping_mask);
95 cpumask_andnot(housekeeping_mask,
96 cpu_possible_mask, non_housekeeping_mask);
97
98 cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask);
99 if (cpumask_empty(tmp)) {
100 pr_warn("Housekeeping: must include one present CPU, "
101 "using boot CPU:%d\n", smp_processor_id());
102 __cpumask_set_cpu(smp_processor_id(), housekeeping_mask);
103 __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);
104 }
105 } else {
106 cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask);
107 if (cpumask_empty(tmp))
108 __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask);
109 cpumask_andnot(tmp, cpu_possible_mask, non_housekeeping_mask);
110 if (!cpumask_equal(tmp, housekeeping_mask)) {
111 pr_warn("Housekeeping: nohz_full= must match isolcpus=\n");
112 free_bootmem_cpumask_var(tmp);
113 free_bootmem_cpumask_var(non_housekeeping_mask);
114 return 0;
115 }
116 }
117 free_bootmem_cpumask_var(tmp);
118
119 if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) {
120 if (IS_ENABLED(CONFIG_NO_HZ_FULL)) {
121 tick_nohz_full_setup(non_housekeeping_mask);
122 } else {
123 pr_warn("Housekeeping: nohz unsupported."
124 " Build with CONFIG_NO_HZ_FULL\n");
125 free_bootmem_cpumask_var(non_housekeeping_mask);
126 return 0;
127 }
128 }
129
130 housekeeping_flags |= flags;
131
132 free_bootmem_cpumask_var(non_housekeeping_mask);
133
134 return 1;
135}
136
137static int __init housekeeping_nohz_full_setup(char *str)
138{
139 unsigned int flags;
140
141 flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU |
142 HK_FLAG_MISC | HK_FLAG_KTHREAD;
143
144 return housekeeping_setup(str, flags);
145}
146__setup("nohz_full=", housekeeping_nohz_full_setup);
147
148static int __init housekeeping_isolcpus_setup(char *str)
149{
150 unsigned int flags = 0;
151 bool illegal = false;
152 char *par;
153 int len;
154
155 while (isalpha(*str)) {
156 if (!strncmp(str, "nohz,", 5)) {
157 str += 5;
158 flags |= HK_FLAG_TICK;
159 continue;
160 }
161
162 if (!strncmp(str, "domain,", 7)) {
163 str += 7;
164 flags |= HK_FLAG_DOMAIN;
165 continue;
166 }
167
168 if (!strncmp(str, "managed_irq,", 12)) {
169 str += 12;
170 flags |= HK_FLAG_MANAGED_IRQ;
171 continue;
172 }
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177
178 for (par = str, len = 0; *str && *str != ','; str++, len++) {
179 if (!isalpha(*str) && *str != '_')
180 illegal = true;
181 }
182
183 if (illegal) {
184 pr_warn("isolcpus: Invalid flag %.*s\n", len, par);
185 return 0;
186 }
187
188 pr_info("isolcpus: Skipped unknown flag %.*s\n", len, par);
189 str++;
190 }
191
192
193 if (!flags)
194 flags |= HK_FLAG_DOMAIN;
195
196 return housekeeping_setup(str, flags);
197}
198__setup("isolcpus=", housekeeping_isolcpus_setup);
199
