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Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
78634061 FW |
2 | /* |
3 | * Housekeeping management. Manage the targets for routine code that can run on | |
4 | * any CPU: unbound workqueues, timers, kthreads and any offloadable work. | |
5 | * | |
6 | * Copyright (C) 2017 Red Hat, Inc., Frederic Weisbecker | |
1bda3f80 | 7 | * Copyright (C) 2017-2018 SUSE, Frederic Weisbecker |
78634061 FW |
8 | * |
9 | */ | |
d84b3131 | 10 | #include "sched.h" |
78634061 | 11 | |
dfcb245e IM |
12 | DEFINE_STATIC_KEY_FALSE(housekeeping_overridden); |
13 | EXPORT_SYMBOL_GPL(housekeeping_overridden); | |
7e56a1cf | 14 | static cpumask_var_t housekeeping_mask; |
de201559 | 15 | static unsigned int housekeeping_flags; |
7e56a1cf | 16 | |
0c5f81da WL |
17 | bool housekeeping_enabled(enum hk_flags flags) |
18 | { | |
19 | return !!(housekeeping_flags & flags); | |
20 | } | |
21 | EXPORT_SYMBOL_GPL(housekeeping_enabled); | |
22 | ||
de201559 | 23 | int housekeeping_any_cpu(enum hk_flags flags) |
7e56a1cf | 24 | { |
dfcb245e | 25 | if (static_branch_unlikely(&housekeeping_overridden)) |
de201559 FW |
26 | if (housekeeping_flags & flags) |
27 | return cpumask_any_and(housekeeping_mask, cpu_online_mask); | |
7e56a1cf FW |
28 | return smp_processor_id(); |
29 | } | |
30 | EXPORT_SYMBOL_GPL(housekeeping_any_cpu); | |
31 | ||
de201559 | 32 | const struct cpumask *housekeeping_cpumask(enum hk_flags flags) |
7e56a1cf | 33 | { |
dfcb245e | 34 | if (static_branch_unlikely(&housekeeping_overridden)) |
de201559 FW |
35 | if (housekeeping_flags & flags) |
36 | return housekeeping_mask; | |
7e56a1cf FW |
37 | return cpu_possible_mask; |
38 | } | |
39 | EXPORT_SYMBOL_GPL(housekeeping_cpumask); | |
40 | ||
de201559 | 41 | void housekeeping_affine(struct task_struct *t, enum hk_flags flags) |
7e56a1cf | 42 | { |
dfcb245e | 43 | if (static_branch_unlikely(&housekeeping_overridden)) |
de201559 FW |
44 | if (housekeeping_flags & flags) |
45 | set_cpus_allowed_ptr(t, housekeeping_mask); | |
7e56a1cf FW |
46 | } |
47 | EXPORT_SYMBOL_GPL(housekeeping_affine); | |
48 | ||
de201559 | 49 | bool housekeeping_test_cpu(int cpu, enum hk_flags flags) |
7e56a1cf | 50 | { |
dfcb245e | 51 | if (static_branch_unlikely(&housekeeping_overridden)) |
de201559 FW |
52 | if (housekeeping_flags & flags) |
53 | return cpumask_test_cpu(cpu, housekeeping_mask); | |
7e56a1cf FW |
54 | return true; |
55 | } | |
56 | EXPORT_SYMBOL_GPL(housekeeping_test_cpu); | |
78634061 FW |
57 | |
58 | void __init housekeeping_init(void) | |
59 | { | |
6f1982fe | 60 | if (!housekeeping_flags) |
78634061 FW |
61 | return; |
62 | ||
dfcb245e | 63 | static_branch_enable(&housekeeping_overridden); |
6f1982fe | 64 | |
d84b3131 FW |
65 | if (housekeeping_flags & HK_FLAG_TICK) |
66 | sched_tick_offload_init(); | |
67 | ||
6f1982fe FW |
68 | /* We need at least one CPU to handle housekeeping work */ |
69 | WARN_ON_ONCE(cpumask_empty(housekeeping_mask)); | |
70 | } | |
71 | ||
edb93821 | 72 | static int __init housekeeping_setup(char *str, enum hk_flags flags) |
6f1982fe FW |
73 | { |
74 | cpumask_var_t non_housekeeping_mask; | |
9219565a | 75 | cpumask_var_t tmp; |
edb93821 | 76 | int err; |
6f1982fe FW |
77 | |
78 | alloc_bootmem_cpumask_var(&non_housekeeping_mask); | |
edb93821 FW |
79 | err = cpulist_parse(str, non_housekeeping_mask); |
80 | if (err < 0 || cpumask_last(non_housekeeping_mask) >= nr_cpu_ids) { | |
81 | pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n"); | |
6f1982fe FW |
82 | free_bootmem_cpumask_var(non_housekeeping_mask); |
83 | return 0; | |
78634061 FW |
84 | } |
85 | ||
9219565a | 86 | alloc_bootmem_cpumask_var(&tmp); |
edb93821 FW |
87 | if (!housekeeping_flags) { |
88 | alloc_bootmem_cpumask_var(&housekeeping_mask); | |
89 | cpumask_andnot(housekeeping_mask, | |
90 | cpu_possible_mask, non_housekeeping_mask); | |
9219565a NP |
91 | |
92 | cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask); | |
93 | if (cpumask_empty(tmp)) { | |
94 | pr_warn("Housekeeping: must include one present CPU, " | |
95 | "using boot CPU:%d\n", smp_processor_id()); | |
c89d92ed | 96 | __cpumask_set_cpu(smp_processor_id(), housekeeping_mask); |
9219565a NP |
97 | __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); |
98 | } | |
edb93821 | 99 | } else { |
9219565a NP |
100 | cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask); |
101 | if (cpumask_empty(tmp)) | |
102 | __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); | |
edb93821 FW |
103 | cpumask_andnot(tmp, cpu_possible_mask, non_housekeeping_mask); |
104 | if (!cpumask_equal(tmp, housekeeping_mask)) { | |
105 | pr_warn("Housekeeping: nohz_full= must match isolcpus=\n"); | |
106 | free_bootmem_cpumask_var(tmp); | |
107 | free_bootmem_cpumask_var(non_housekeeping_mask); | |
108 | return 0; | |
109 | } | |
edb93821 | 110 | } |
9219565a | 111 | free_bootmem_cpumask_var(tmp); |
de201559 | 112 | |
edb93821 FW |
113 | if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) { |
114 | if (IS_ENABLED(CONFIG_NO_HZ_FULL)) { | |
115 | tick_nohz_full_setup(non_housekeeping_mask); | |
116 | } else { | |
117 | pr_warn("Housekeeping: nohz unsupported." | |
118 | " Build with CONFIG_NO_HZ_FULL\n"); | |
119 | free_bootmem_cpumask_var(non_housekeeping_mask); | |
120 | return 0; | |
121 | } | |
122 | } | |
e179f5a0 | 123 | |
edb93821 | 124 | housekeeping_flags |= flags; |
6f1982fe FW |
125 | |
126 | free_bootmem_cpumask_var(non_housekeeping_mask); | |
127 | ||
128 | return 1; | |
78634061 | 129 | } |
edb93821 FW |
130 | |
131 | static int __init housekeeping_nohz_full_setup(char *str) | |
132 | { | |
133 | unsigned int flags; | |
134 | ||
1bda3f80 | 135 | flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC; |
edb93821 FW |
136 | |
137 | return housekeeping_setup(str, flags); | |
138 | } | |
6f1982fe | 139 | __setup("nohz_full=", housekeeping_nohz_full_setup); |
edb93821 FW |
140 | |
141 | static int __init housekeeping_isolcpus_setup(char *str) | |
142 | { | |
150dfee9 FW |
143 | unsigned int flags = 0; |
144 | ||
145 | while (isalpha(*str)) { | |
146 | if (!strncmp(str, "nohz,", 5)) { | |
147 | str += 5; | |
148 | flags |= HK_FLAG_TICK; | |
149 | continue; | |
150 | } | |
151 | ||
152 | if (!strncmp(str, "domain,", 7)) { | |
153 | str += 7; | |
154 | flags |= HK_FLAG_DOMAIN; | |
155 | continue; | |
156 | } | |
157 | ||
158 | pr_warn("isolcpus: Error, unknown flag\n"); | |
159 | return 0; | |
160 | } | |
161 | ||
162 | /* Default behaviour for isolcpus without flags */ | |
163 | if (!flags) | |
164 | flags |= HK_FLAG_DOMAIN; | |
165 | ||
166 | return housekeeping_setup(str, flags); | |
edb93821 FW |
167 | } |
168 | __setup("isolcpus=", housekeeping_isolcpus_setup); |